257656320 has 240 divisors, whose sum is σ = 913481712. Its totient is φ = 67092480.

The previous prime is 257656307. The next prime is 257656361. The reversal of 257656320 is 23656752.

It is a happy number.

257656320 is a `hidden beast` number, since 2 + 5 + 76 + 563 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1221015 + ... + 1221225.

Almost surely, 2^257656320 is an apocalyptic number.

257656320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257656320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (456740856).

257656320 is an abundant number, since it is smaller than the sum of its proper divisors (655825392).

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

257656320 is a wasteful number, since it uses less digits than its factorization.

257656320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 36.

The square root of 257656320 is about 16051.6765479497. The cubic root of 257656320 is about 636.3268759965.

The spelling of 257656320 in words is "two hundred fifty-seven million, six hundred fifty-six thousand, three hundred twenty".