256125731 has 4 divisors (see below), whose sum is σ = 256647864. Its totient is φ = 255603600.

The previous prime is 256125703. The next prime is 256125739. The reversal of 256125731 is 137521652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256125731 is a prime.

It is a super-2 number, since 2×256125731² = 131200780160568722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256125739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260330 + ... + 261311.

It is an arithmetic number, because the mean of its divisors is an integer number (64161966).

Almost surely, 2^256125731 is an apocalyptic number.

256125731 is a deficient number, since it is larger than the sum of its proper divisors (522133).

256125731 is an equidigital number, since it uses as much as digits as its factorization.

256125731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522132.

The product of its digits is 12600, while the sum is 32.

The square root of 256125731 is about 16003.9286114379. The cubic root of 256125731 is about 635.0643545664.

The spelling of 256125731 in words is "two hundred fifty-six million, one hundred twenty-five thousand, seven hundred thirty-one".