256784831 has 2 divisors, whose sum is σ = 256784832. Its totient is φ = 256784830.

The previous prime is 256784809. The next prime is 256784833. The reversal of 256784831 is 138487652.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256784831 is a prime.

It is a super-2 number, since 2×256784831² = 131876898863397122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 256784833, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256784833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128392415 + 128392416.

It is an arithmetic number, because the mean of its divisors is an integer number (128392416).

Almost surely, 2^256784831 is an apocalyptic number.

256784831 is a deficient number, since it is larger than the sum of its proper divisors (1).

256784831 is an equidigital number, since it uses as much as digits as its factorization.

256784831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 322560, while the sum is 44.

The square root of 256784831 is about 16024.5071999110. The cubic root of 256784831 is about 635.6086346281.

The spelling of 256784831 in words is "two hundred fifty-six million, seven hundred eighty-four thousand, eight hundred thirty-one".