256747376449 has 2 divisors, whose sum is σ = 256747376450. Its totient is φ = 256747376448.

The previous prime is 256747376429. The next prime is 256747376497. The reversal of 256747376449 is 944673747652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 240264668224 + 16482708225 = 490168^2 + 128385^2 .

It is a cyclic number.

It is not a de Polignac number, because 256747376449 - 2²⁷ = 256613158721 is a prime.

It is not a weakly prime, because it can be changed into another prime (256747376419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128373688224 + 128373688225.

It is an arithmetic number, because the mean of its divisors is an integer number (128373688225).

Almost surely, 2^256747376449 is an apocalyptic number.

It is an amenable number.

256747376449 is a deficient number, since it is larger than the sum of its proper divisors (1).

256747376449 is an equidigital number, since it uses as much as digits as its factorization.

256747376449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 213373440, while the sum is 64.

The spelling of 256747376449 in words is "two hundred fifty-six billion, seven hundred forty-seven million, three hundred seventy-six thousand, four hundred forty-nine".