256564829 has 2 divisors, whose sum is σ = 256564830. Its totient is φ = 256564828.

The previous prime is 256564801. The next prime is 256564831. The reversal of 256564829 is 928465652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133864900 + 122699929 = 11570^2 + 11077^2 .

It is a cyclic number.

It is not a de Polignac number, because 256564829 - 2¹⁶ = 256499293 is a prime.

It is a super-2 number, since 2×256564829² = 131651022959598482, which contains 22 as substring.

Together with 256564831, 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 (256564849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128282414 + 128282415.

It is an arithmetic number, because the mean of its divisors is an integer number (128282415).

Almost surely, 2^256564829 is an apocalyptic number.

It is an amenable number.

256564829 is a deficient number, since it is larger than the sum of its proper divisors (1).

256564829 is an equidigital number, since it uses as much as digits as its factorization.

256564829 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1036800, while the sum is 47.

The square root of 256564829 is about 16017.6411808980. The cubic root of 256564829 is about 635.4270622144.

The spelling of 256564829 in words is "two hundred fifty-six million, five hundred sixty-four thousand, eight hundred twenty-nine".