256409579 has 4 divisors (see below), whose sum is σ = 269904840. Its totient is φ = 242914320.

The previous prime is 256409563. The next prime is 256409597. The reversal of 256409579 is 975904652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256409579 - 2⁴ = 256409563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256409599) 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 in 3 ways as a sum of consecutive naturals, for example, 6747602 + ... + 6747639.

It is an arithmetic number, because the mean of its divisors is an integer number (67476210).

Almost surely, 2^256409579 is an apocalyptic number.

256409579 is a deficient number, since it is larger than the sum of its proper divisors (13495261).

256409579 is a wasteful number, since it uses less digits than its factorization.

256409579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13495260.

The product of its (nonzero) digits is 680400, while the sum is 47.

The square root of 256409579 is about 16012.7942283663. The cubic root of 256409579 is about 635.2988685507.

The spelling of 256409579 in words is "two hundred fifty-six million, four hundred nine thousand, five hundred seventy-nine".