257645232864 has 336 divisors, whose sum is σ = 806344398720. Its totient is φ = 80856714240.

The previous prime is 257645232839. The next prime is 257645232899. The reversal of 257645232864 is 468232546752.

257645232864 is a `hidden beast` number, since 2 + 57 + 6 + 4 + 523 + 2 + 8 + 64 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 257645232864.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 26752402 + ... + 26762030.

It is an arithmetic number, because the mean of its divisors is an integer number (2399834520).

Almost surely, 2^257645232864 is an apocalyptic number.

257645232864 is a gapful number since it is divisible by the number (24) 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 257645232864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (403172199360).

257645232864 is an abundant number, since it is smaller than the sum of its proper divisors (548699165856).

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

257645232864 is an equidigital number, since it uses as much as digits as its factorization.

257645232864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9725 (or 9702 counting only the distinct ones).

The product of its digits is 19353600, while the sum is 54.

The spelling of 257645232864 in words is "two hundred fifty-seven billion, six hundred forty-five million, two hundred thirty-two thousand, eight hundred sixty-four".