256115557 has 24 divisors (see below), whose sum is σ = 289650816. Its totient is φ = 225907968.

The previous prime is 256115539. The next prime is 256115579. The reversal of 256115557 is 755511652.

It is not a de Polignac number, because 256115557 - 2²³ = 247726949 is a prime.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256115537) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 351928 + ... + 352654.

It is an arithmetic number, because the mean of its divisors is an integer number (12068784).

Almost surely, 2^256115557 is an apocalyptic number.

It is an amenable number.

256115557 is a deficient number, since it is larger than the sum of its proper divisors (33535259).

256115557 is a wasteful number, since it uses less digits than its factorization.

256115557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 837 (or 820 counting only the distinct ones).

The product of its digits is 52500, while the sum is 37.

The square root of 256115557 is about 16003.6107488279. The cubic root of 256115557 is about 635.0559456361.

The spelling of 256115557 in words is "two hundred fifty-six million, one hundred fifteen thousand, five hundred fifty-seven".