256657400725 has 48 divisors (see below), whose sum is σ = 349408886400. Its totient is φ = 185469523200.

The previous prime is 256657400711. The next prime is 256657400743. The reversal of 256657400725 is 527004756652.

It is not a de Polignac number, because 256657400725 - 2¹³ = 256657392533 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28116112 + ... + 28125238.

It is an arithmetic number, because the mean of its divisors is an integer number (7279351800).

Almost surely, 2^256657400725 is an apocalyptic number.

256657400725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

256657400725 is a deficient number, since it is larger than the sum of its proper divisors (92751485675).

256657400725 is a wasteful number, since it uses less digits than its factorization.

256657400725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9790 (or 9785 counting only the distinct ones).

The product of its (nonzero) digits is 3528000, while the sum is 49.

The spelling of 256657400725 in words is "two hundred fifty-six billion, six hundred fifty-seven million, four hundred thousand, seven hundred twenty-five".