256274877497 has 2 divisors, whose sum is σ = 256274877498. Its totient is φ = 256274877496.

The previous prime is 256274877479. The next prime is 256274877499. The reversal of 256274877497 is 794778472652.

Together with previous prime (256274877479) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 237499300921 + 18775576576 = 487339^2 + 137024^2 .

It is a cyclic number.

It is not a de Polignac number, because 256274877497 - 2²⁴ = 256258100281 is a prime.

It is a super-2 number, since 2×256274877497² (a number of 24 digits) contains 22 as substring.

Together with 256274877499, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256274877499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128137438748 + 128137438749.

It is an arithmetic number, because the mean of its divisors is an integer number (128137438749).

Almost surely, 2^256274877497 is an apocalyptic number.

It is an amenable number.

256274877497 is a deficient number, since it is larger than the sum of its proper divisors (1).

256274877497 is an equidigital number, since it uses as much as digits as its factorization.

256274877497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 331914240, while the sum is 68.

The spelling of 256274877497 in words is "two hundred fifty-six billion, two hundred seventy-four million, eight hundred seventy-seven thousand, four hundred ninety-seven".