256501697 has 2 divisors, whose sum is σ = 256501698. Its totient is φ = 256501696.

The previous prime is 256501667. The next prime is 256501709. The reversal of 256501697 is 796105652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208629136 + 47872561 = 14444^2 + 6919^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256501697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256501667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128250848 + 128250849.

It is an arithmetic number, because the mean of its divisors is an integer number (128250849).

Almost surely, 2^256501697 is an apocalyptic number.

It is an amenable number.

256501697 is a deficient number, since it is larger than the sum of its proper divisors (1).

256501697 is an equidigital number, since it uses as much as digits as its factorization.

256501697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 113400, while the sum is 41.

The square root of 256501697 is about 16015.6703574967. The cubic root of 256501697 is about 635.3749388423.

The spelling of 256501697 in words is "two hundred fifty-six million, five hundred one thousand, six hundred ninety-seven".