838

838 = 2 x 419. It is a palindrome with exactly two prime factors (A046328). Both prime factors are distinct Sophie Germain primes (A157344). The sum of its prime factors is a prime (A108605): 2 + 419 = 421.

838 is a happy number.

838 and 838² = 702244 have the same digit sum (A058369).

838 is the number of primes between 140,000 and 150,000 (A038824).

838 is the integer part of the surface area of a regular tetrahedron with edge length 22 (A171972).

Source: On-Line Encyclopedia of Integer Sequences

1527

1527 = 3 x 509.

1527 has the representation  3 x 2⁹ - 9.

1527 is the lower of a pair of consecutive happy numbers (A035502).

1527 is the sum of eight nonzero sixth powers (A003364).

The sum of the distinct prime factors of 1527 is a cube (A164788): 3 + 509 = 512 = 8³.

Mathematician John Dee was born in the year 1527.

Source: On-Line Encyclopedia of Integer Sequences

632

632 = 2³ x 79.

632 is a happy number. Take the sum of the squares of the digits of a number. Repeat the operation. If the result is eventually 1, the original number is happy: 6² + 3² + 2² = 49; 4² + 9² = 97; 9² + 7² = 130; 1² + 3² + 0² = 10; 1² + 0² = 1.

632 is the number of different necklaces (that can't be turned over) possible with 13 beads, each bead being one of 2 colors.

632 is a member of the following sequence: Start with 1 and repeatedly reverse the digits and add 7 to the next term: 1, 8, 15, 58, 92, 36, . . . 526, 632, 243., . . .


The prophet Muhammad, founder of Islam, died in the year 632.

Source: Number Gossip