256634731 has 2 divisors, whose sum is σ = 256634732. Its totient is φ = 256634730.

The previous prime is 256634687. The next prime is 256634753. The reversal of 256634731 is 137436652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256634731 - 2⁹ = 256634219 is a prime.

It is a super-2 number, since 2×256634731² = 131722770310884722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256634761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128317365 + 128317366.

It is an arithmetic number, because the mean of its divisors is an integer number (128317366).

Almost surely, 2^256634731 is an apocalyptic number.

256634731 is a deficient number, since it is larger than the sum of its proper divisors (1).

256634731 is an equidigital number, since it uses as much as digits as its factorization.

256634731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 37.

The square root of 256634731 is about 16019.8230639417. The cubic root of 256634731 is about 635.4847650951.

The spelling of 256634731 in words is "two hundred fifty-six million, six hundred thirty-four thousand, seven hundred thirty-one".