257628868 has 18 divisors (see below), whose sum is σ = 524459166. Its totient is φ = 110412288.

The previous prime is 257628859. The next prime is 257628887. The reversal of 257628868 is 868826752.

It can be written as a sum of positive squares in only one way, i.e., 134374464 + 123254404 = 11592^2 + 11102^2 .

It is a super-2 number, since 2×257628868² = 132745267253922848, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 657021 + ... + 657412.

Almost surely, 2^257628868 is an apocalyptic number.

257628868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

257628868 is an abundant number, since it is smaller than the sum of its proper divisors (266830298).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

257628868 is a wasteful number, since it uses less digits than its factorization.

257628868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1314451 (or 1314442 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 52.

The square root of 257628868 is about 16050.8214120026. The cubic root of 257628868 is about 636.3042760388.

The spelling of 257628868 in words is "two hundred fifty-seven million, six hundred twenty-eight thousand, eight hundred sixty-eight".