1933

1933 is a prime number.

1931 and 1933 form a twin prime pair.

1933 is centered heptagonal number (A069099).

1933 = (1⁹ + 2⁸ + 3⁷ + 4⁶ + 5⁵)/5.

1933 has a representation as the sum of two squares: 1933 = 13² + 42².

1933 is the hypotenuse of a primitive Pythagorean triple: 1933² = 1092² + 1595².

1933 divides 10²¹ - 1.

Source: Prime Curios!

6623

6623 = 37 x 179.

6623 has the property that the sum of its prime factors is equal to the product of its digits (A067173).

6623 is a centered heptagonal number (A069099).

6623 is a number n such that the nth and the (n + 1)th primes have the same sum of their digits squared (A109182).

6623 is a member of the Fibonacci-like sequence beginning with 12 and 67 (A091074).

6623 is a number that cannot be written as a sum of three squares.

Source: What's Special About This Number?

7246

7246 = 2 x 3623.

7246 is a centered heptagonal number (A069099).

7246 is a semiprime centered triangular number (A184481).

7246 is 16116 in base 8.

2⁷²⁴⁶ + 3⁷²⁴⁶ is a semiprime (A050244).

Source: On-Line Encyclopedia of Integer Sequences

5461

5461 = 43 x 127.

5461 is 1010101010101 in binary (base 2).

5461 is 1111111 in base 4 (A053716). It divides 4⁷ - 1.

5461 is a centered heptagonal number (A069099). It is also an octagonal (star) number (A000567) and a concentric tridecagonal number (A195045).

5461 is a Poulet number.

Source: What's Special About This Number?

3046

3046 = 2 x 1523.

3046 is the product of two primes whose difference is a perfect square (A143416): 1523 - 2 = 1521 =  39².

3046 is 11611 in base 7 (A043015 and A043400).

3046 is a centered heptagonal number (A069099).

3046 is a number n such that n² is palidromic in base 3 (122110101011221) (A029984).

3046 is the sum of the first 23 isolated (single or non-twin) primes (A153478).

Source: On-Line Encyclopedia of Integer Sequences

463

463 is a prime number.

461 and 463 form a twin prime pair.

463 is a centered heptagonal number.

463 is the smallest multidigit prime such that both the sum of the digits and the product of the digits of its square remain square.

463 divided by 595 is an excellent approximation to the common logarithm of 6.

463 is 111001111 in base 2 (binary).

463 is a divisor of 21³ - 1.

463 meters is exactly one-fourth of an international nautical mile.

Source: Prime Curios!

547

547 is a prime number.

547 is a centered hexagonal number (or hex number) and a centered heptagonal number.

The number of primes between 6! and 7! is itself prime. 547 is the smallest odd prime to enumerate the primes between n! and (n + 1)! for any n.

547 is the smallest number that cannot be written using 11 copies of 11 and the operations +, -, x, /.

547 is 202021 in base 3 and 20203 in base 4. It is 4142 in base 4.

Source: Prime Curios!

841

841 = 29 x 29.

841 is a centered square number. It is also a centered heptagonal number and a centered octagonal number.

841 has a representation as a sum of two squares: 841 = 20² + 21². It is the sum of two consecutive squares.

841 is the hypotenuse of a primitive Pythagorean triple: 841² = 41² + 840².

841 is the smallest 3-digit square whose digits are decreasing.

841 is the smallest binary prime square. It's a perfect square whose binary representation (1101001001) considered as a decimal is a prime number.

841 is a divisor of 41⁴ - 1.

Source: Number Gossip

386

386 = 2 x 193.

386 has a representation as a sum of two squares: 386 = 5² + 19².

386 is a centered heptagonal number.

386 is the number of regions into which the complex plane is cut by drawing lines between all pairs of 11th roots of unity.

386 is 282 in base 12.

Source: What's Special About This Number?

197

197 is a prime number.

197 is a centered heptagonal number.

197 is the sum of the first 12 primes: 197 = 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37. It is also the smallest prime that is the sum of seven consecutive primes: 197 = 17 + 19 + 23 + 29 + 31 + 37 + 41.

197 is the sum of the digits of all two-digit primes.

197 is the sum of the squares of all composite digits: 197 = 4² + 6² + 8² + 9².

197 has a representation as a sum of two squares: 197 = 1² + 14².

197 and 199 form a twin prime pair.

197 is the hypotenuse of a primitive Pythagorean triple: 197² = 28² + 195².

The chemical element gold has one stable isotope, which has a total of 197 neutrons and protons in its nucleus.

Source: Prime Curios!

106

106 = 2 x 53.

106 has a representation as a sum of two squares: 106 = 5² + 9².

106 is a divisor of 23⁴ - 1.

106 = 25 + 26 + 27 + 28.

15 straight cuts through a pizza can produce as many as 106 pieces.

106 is a centered pentagonal number and a centered heptagonal number.

The sum of the first 106 digits of pi is a prime.

Messier 106 is a bright spiral galaxy in the constellation Canes Venatici.

Source: Prime Curios!

148

148 = 2² x 37.

148 has a representation as a sum of two squares: 148 = 2² + 12².

148 is a heptagonal number. It is also a centered heptagonal number.

148 is the number of perfect graphs with six vertices.

148 x (14 + 8) = 14³ + 8³ = 3256.

Three square numbers using the same digits: 148² = 21904; 203² = 41209; and 302² = 91204.

The astronomical object Arp 148 is the spectacular aftermath of an encounter between two galaxies.

Source: Numeropedia

316

316 = 2² x 79.

316 is a number that cannot be written as a sum of three squares.

316 is a centered triangular number. It is also a centered heptagonal number.

316 has a digit product that is the digit sum of (3¹)⁶ = 729: 3 x 1 x 6 = 18; and 7 + 2 + 9 = 18.

316 is the telephone area code for the city of Wichita, Kansas.

Source: What's Special About This Number?

638

638 = 2 x 11 x 29.

638 is the sum of four consecutive primes: 151 + 157 + 163 + 167 = 638.

638 is the solution to the postage stamp problem for 7 denominations and 6 stamps.


638 is a centered heptagonal number.


The Islamic calendar was introduced in the year 638.

Source: Wikipedia