257565231 has 64 divisors (see below), whose sum is σ = 478694400. Its totient is φ = 132969600.

The previous prime is 257565229. The next prime is 257565233. The reversal of 257565231 is 132565752.

257565231 is a `hidden beast` number, since 2 + 575 + 6 + 52 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (257565229) and next prime (257565233).

It is not a de Polignac number, because 257565231 - 2¹ = 257565229 is a prime.

It is a super-2 number, since 2×257565231² = 132679696440166722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257565233) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 475821 + ... + 476361.

It is an arithmetic number, because the mean of its divisors is an integer number (7479600).

Almost surely, 2^257565231 is an apocalyptic number.

257565231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

257565231 is a deficient number, since it is larger than the sum of its proper divisors (221129169).

257565231 is a wasteful number, since it uses less digits than its factorization.

257565231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797 (or 791 counting only the distinct ones).

The product of its digits is 63000, while the sum is 36.

The square root of 257565231 is about 16048.8389299662. The cubic root of 257565231 is about 636.2518804745.

The spelling of 257565231 in words is "two hundred fifty-seven million, five hundred sixty-five thousand, two hundred thirty-one".