256210657 has 2 divisors, whose sum is σ = 256210658. Its totient is φ = 256210656.

The previous prime is 256210637. The next prime is 256210693. The reversal of 256210657 is 756012652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159365376 + 96845281 = 12624^2 + 9841^2 .

It is a cyclic number.

It is not a de Polignac number, because 256210657 - 2²⁷ = 121992929 is a prime.

It is not a weakly prime, because it can be changed into another prime (256210637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128105328 + 128105329.

It is an arithmetic number, because the mean of its divisors is an integer number (128105329).

Almost surely, 2^256210657 is an apocalyptic number.

It is an amenable number.

256210657 is a deficient number, since it is larger than the sum of its proper divisors (1).

256210657 is an equidigital number, since it uses as much as digits as its factorization.

256210657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 256210657 is about 16006.5816775475. The cubic root of 256210657 is about 635.1345382157.

The spelling of 256210657 in words is "two hundred fifty-six million, two hundred ten thousand, six hundred fifty-seven".