257660928 has 144 divisors (see below), whose sum is σ = 850908240. Its totient is φ = 73580544.

The previous prime is 257660899. The next prime is 257660929. The reversal of 257660928 is 829066752.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257660929) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 128026 + ... + 130022.

It is an arithmetic number, because the mean of its divisors is an integer number (5909085).

Almost surely, 2^257660928 is an apocalyptic number.

257660928 is a gapful number since it is divisible by the number (28) 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 257660928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (425454120).

257660928 is an abundant number, since it is smaller than the sum of its proper divisors (593247312).

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

257660928 is a wasteful number, since it uses less digits than its factorization.

257660928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2032 (or 2009 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 257660928 is about 16051.8200837164. The cubic root of 257660928 is about 636.3306693917.

It can be divided in two parts, 2576 and 60928, that added together give a square (63504 = 252²).

The spelling of 257660928 in words is "two hundred fifty-seven million, six hundred sixty thousand, nine hundred twenty-eight".