257521680 has 240 divisors, whose sum is σ = 966813120. Its totient is φ = 63327744.

The previous prime is 257521679. The next prime is 257521699. The reversal of 257521680 is 86125752.

It is a happy number.

257521680 is a `hidden beast` number, since 2 + 57 + 521 + 6 + 80 = 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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 252211 + ... + 253229.

It is an arithmetic number, because the mean of its divisors is an integer number (4028388).

Almost surely, 2^257521680 is an apocalyptic number.

257521680 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 257521680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (483406560).

257521680 is an abundant number, since it is smaller than the sum of its proper divisors (709291440).

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

257521680 is a wasteful number, since it uses less digits than its factorization.

257521680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060 (or 1042 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 257521680 is about 16047.4820454799. The cubic root of 257521680 is about 636.2160177568.

The spelling of 257521680 in words is "two hundred fifty-seven million, five hundred twenty-one thousand, six hundred eighty".