5415

5415 = 3 x 5 x 19 x 19.

5415 is a number n such that n and its reversal (5145) are both multiples of 15 (A062905).

5415 is a number n such that the sum of the digits of n equals the squarefree part of n (A070274).

5415 is the smallest number n such that 2n + 1, 4n + 1, 6n + 1, 8n + 1, and 10n + 1 are all prime numbers (A124410).

5415 is a number that cannot be written as a sum of three squares.

5415 is a divisor of 68¹² - 1.

Source: On-Line Encyclopedia of Integer Sequences