256668697 has 2 divisors, whose sum is σ = 256668698. Its totient is φ = 256668696.

The previous prime is 256668691. The next prime is 256668719. The reversal of 256668697 is 796866652.

It is a happy number.

256668697 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 243859456 + 12809241 = 15616^2 + 3579^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256668697 is a prime.

It is not a weakly prime, because it can be changed into another prime (256668691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128334348 + 128334349.

It is an arithmetic number, because the mean of its divisors is an integer number (128334349).

Almost surely, 2^256668697 is an apocalyptic number.

It is an amenable number.

256668697 is a deficient number, since it is larger than the sum of its proper divisors (1).

256668697 is an equidigital number, since it uses as much as digits as its factorization.

256668697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6531840, while the sum is 55.

The square root of 256668697 is about 16020.8831529351. The cubic root of 256668697 is about 635.5127996526.

The spelling of 256668697 in words is "two hundred fifty-six million, six hundred sixty-eight thousand, six hundred ninety-seven".