256617623 has 2 divisors, whose sum is σ = 256617624. Its totient is φ = 256617622.

The previous prime is 256617617. The next prime is 256617649. The reversal of 256617623 is 326716652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256617623 - 2⁸ = 256617367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256617653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128308811 + 128308812.

It is an arithmetic number, because the mean of its divisors is an integer number (128308812).

Almost surely, 2^256617623 is an apocalyptic number.

256617623 is a deficient number, since it is larger than the sum of its proper divisors (1).

256617623 is an equidigital number, since it uses as much as digits as its factorization.

256617623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 38.

The square root of 256617623 is about 16019.2890915920. The cubic root of 256617623 is about 635.4706437082.

The spelling of 256617623 in words is "two hundred fifty-six million, six hundred seventeen thousand, six hundred twenty-three".