257691920640 has 576 divisors, whose sum is σ = 1029573199872. Its totient is φ = 53364326400.

The previous prime is 257691920593. The next prime is 257691920653. The reversal of 257691920640 is 46029196752.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 97868764 + ... + 97871396.

It is an arithmetic number, because the mean of its divisors is an integer number (1787453472).

Almost surely, 2^257691920640 is an apocalyptic number.

257691920640 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 257691920640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (514786599936).

257691920640 is an abundant number, since it is smaller than the sum of its proper divisors (771881279232).

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

257691920640 is a wasteful number, since it uses less digits than its factorization.

257691920640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3006 (or 2992 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 51.

The spelling of 257691920640 in words is "two hundred fifty-seven billion, six hundred ninety-one million, nine hundred twenty thousand, six hundred forty".