256620439 has 2 divisors, whose sum is σ = 256620440. Its totient is φ = 256620438.

The previous prime is 256620421. The next prime is 256620461. The reversal of 256620439 is 934026652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256620439 - 2⁷ = 256620311 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256620398 and 256620407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256620239) 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, 128310219 + 128310220.

It is an arithmetic number, because the mean of its divisors is an integer number (128310220).

Almost surely, 2^256620439 is an apocalyptic number.

256620439 is a deficient number, since it is larger than the sum of its proper divisors (1).

256620439 is an equidigital number, since it uses as much as digits as its factorization.

256620439 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 256620439 is about 16019.3769853887. The cubic root of 256620439 is about 635.4729681508.

It can be divided in two parts, 2566 and 20439, that added together give a triangular number (23005 = T₂₁₄).

The spelling of 256620439 in words is "two hundred fifty-six million, six hundred twenty thousand, four hundred thirty-nine".