256561635 has 32 divisors (see below), whose sum is σ = 452874240. Its totient is φ = 122988800.

The previous prime is 256561631. The next prime is 256561651. The reversal of 256561635 is 536165652.

It is not a de Polignac number, because 256561635 - 2² = 256561631 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256561593 and 256561602.

It is not an unprimeable number, because it can be changed into a prime (256561631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5950 + ... + 23420.

It is an arithmetic number, because the mean of its divisors is an integer number (14152320).

Almost surely, 2^256561635 is an apocalyptic number.

256561635 is a deficient number, since it is larger than the sum of its proper divisors (196312605).

256561635 is a wasteful number, since it uses less digits than its factorization.

256561635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17579.

The product of its digits is 162000, while the sum is 39.

The square root of 256561635 is about 16017.5414780172. The cubic root of 256561635 is about 635.4244253727.

The spelling of 256561635 in words is "two hundred fifty-six million, five hundred sixty-one thousand, six hundred thirty-five".