256668757 has 2 divisors, whose sum is σ = 256668758. Its totient is φ = 256668756.

The previous prime is 256668751. The next prime is 256668761. The reversal of 256668757 is 757866652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188622756 + 68046001 = 13734^2 + 8249^2 .

It is a cyclic number.

It is not a de Polignac number, because 256668757 - 2³ = 256668749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256668751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128334378 + 128334379.

It is an arithmetic number, because the mean of its divisors is an integer number (128334379).

Almost surely, 2^256668757 is an apocalyptic number.

It is an amenable number.

256668757 is a deficient number, since it is larger than the sum of its proper divisors (1).

256668757 is an equidigital number, since it uses as much as digits as its factorization.

256668757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4233600, while the sum is 52.

The square root of 256668757 is about 16020.8850254909. The cubic root of 256668757 is about 635.5128491726.

The spelling of 256668757 in words is "two hundred fifty-six million, six hundred sixty-eight thousand, seven hundred fifty-seven".