256409599 has 2 divisors, whose sum is σ = 256409600. Its totient is φ = 256409598.

The previous prime is 256409597. The next prime is 256409633. The reversal of 256409599 is 995904652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256409599 - 2¹ = 256409597 is a prime.

Together with 256409597, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256409597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128204799 + 128204800.

It is an arithmetic number, because the mean of its divisors is an integer number (128204800).

Almost surely, 2^256409599 is an apocalyptic number.

256409599 is a deficient number, since it is larger than the sum of its proper divisors (1).

256409599 is an equidigital number, since it uses as much as digits as its factorization.

256409599 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 874800, while the sum is 49.

The square root of 256409599 is about 16012.7948528669. The cubic root of 256409599 is about 635.2988850686.

The spelling of 256409599 in words is "two hundred fifty-six million, four hundred nine thousand, five hundred ninety-nine".