256677657 has 4 divisors (see below), whose sum is σ = 342236880. Its totient is φ = 171118436.

The previous prime is 256677653. The next prime is 256677661. The reversal of 256677657 is 756776652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (256677653) and next prime (256677661).

It is a cyclic number.

It is not a de Polignac number, because 256677657 - 2² = 256677653 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256677653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42779607 + ... + 42779612.

It is an arithmetic number, because the mean of its divisors is an integer number (85559220).

Almost surely, 2^256677657 is an apocalyptic number.

It is an amenable number.

256677657 is a deficient number, since it is larger than the sum of its proper divisors (85559223).

256677657 is an equidigital number, since it uses as much as digits as its factorization.

256677657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85559222.

The product of its digits is 3704400, while the sum is 51.

The square root of 256677657 is about 16021.1627855159. The cubic root of 256677657 is about 635.5201945661.

The spelling of 256677657 in words is "two hundred fifty-six million, six hundred seventy-seven thousand, six hundred fifty-seven".