256909957 has 2 divisors, whose sum is σ = 256909958. Its totient is φ = 256909956.

The previous prime is 256909949. The next prime is 256909973. The reversal of 256909957 is 759909652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 253637476 + 3272481 = 15926^2 + 1809^2 .

It is a cyclic number.

It is not a de Polignac number, because 256909957 - 2³ = 256909949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256909937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128454978 + 128454979.

It is an arithmetic number, because the mean of its divisors is an integer number (128454979).

Almost surely, 2^256909957 is an apocalyptic number.

It is an amenable number.

256909957 is a deficient number, since it is larger than the sum of its proper divisors (1).

256909957 is an equidigital number, since it uses as much as digits as its factorization.

256909957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1530900, while the sum is 52.

The square root of 256909957 is about 16028.4109318422. The cubic root of 256909957 is about 635.7118575628.

The spelling of 256909957 in words is "two hundred fifty-six million, nine hundred nine thousand, nine hundred fifty-seven".