256126621 has 2 divisors, whose sum is σ = 256126622. Its totient is φ = 256126620.

The previous prime is 256126609. The next prime is 256126693. The reversal of 256126621 is 126621652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 241025625 + 15100996 = 15525^2 + 3886^2 .

It is a cyclic number.

It is not a de Polignac number, because 256126621 - 2⁵ = 256126589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256126601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128063310 + 128063311.

It is an arithmetic number, because the mean of its divisors is an integer number (128063311).

Almost surely, 2^256126621 is an apocalyptic number.

It is an amenable number.

256126621 is a deficient number, since it is larger than the sum of its proper divisors (1).

256126621 is an equidigital number, since it uses as much as digits as its factorization.

256126621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 31.

The square root of 256126621 is about 16003.9564170864. The cubic root of 256126621 is about 635.0650901513.

The spelling of 256126621 in words is "two hundred fifty-six million, one hundred twenty-six thousand, six hundred twenty-one".