256511923 has 2 divisors, whose sum is σ = 256511924. Its totient is φ = 256511922.

The previous prime is 256511917. The next prime is 256511953. The reversal of 256511923 is 329115652.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256511923 is a prime.

It is not a weakly prime, because it can be changed into another prime (256511953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128255961 + 128255962.

It is an arithmetic number, because the mean of its divisors is an integer number (128255962).

Almost surely, 2^256511923 is an apocalyptic number.

256511923 is a deficient number, since it is larger than the sum of its proper divisors (1).

256511923 is an equidigital number, since it uses as much as digits as its factorization.

256511923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 34.

The square root of 256511923 is about 16015.9896041425. The cubic root of 256511923 is about 635.3833822663.

The spelling of 256511923 in words is "two hundred fifty-six million, five hundred eleven thousand, nine hundred twenty-three".