257009856 has 56 divisors (see below), whose sum is σ = 690189120. Its totient is φ = 84387072.

The previous prime is 257009783. The next prime is 257009869. The reversal of 257009856 is 658900752.

It is a super-2 number, since 2×257009856² = 132108132162281472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2875 + ... + 22853.

Almost surely, 2^257009856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257009856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345094560).

257009856 is an abundant number, since it is smaller than the sum of its proper divisors (433179264).

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

257009856 is a wasteful number, since it uses less digits than its factorization.

257009856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20061 (or 20051 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 42.

The square root of 257009856 is about 16031.5269391284. The cubic root of 257009856 is about 635.7942453766.

The spelling of 257009856 in words is "two hundred fifty-seven million, nine thousand, eight hundred fifty-six".