256653766657 has 4 divisors (see below), whose sum is σ = 256731238660. Its totient is φ = 256576294656.

The previous prime is 256653766573. The next prime is 256653766661. The reversal of 256653766657 is 756667356652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 243521523441 + 13132243216 = 493479^2 + 114596^2 .

It is a cyclic number.

It is not a de Polignac number, because 256653766657 - 2¹⁹ = 256653242369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256653766697) 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, 38731032 + ... + 38737657.

It is an arithmetic number, because the mean of its divisors is an integer number (64182809665).

Almost surely, 2^256653766657 is an apocalyptic number.

It is an amenable number.

256653766657 is a deficient number, since it is larger than the sum of its proper divisors (77472003).

256653766657 is an equidigital number, since it uses as much as digits as its factorization.

256653766657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77472002.

The product of its digits is 285768000, while the sum is 64.

The spelling of 256653766657 in words is "two hundred fifty-six billion, six hundred fifty-three million, seven hundred sixty-six thousand, six hundred fifty-seven".