256635490 has 16 divisors (see below), whose sum is σ = 462138552. Its totient is φ = 102610944.

The previous prime is 256635469. The next prime is 256635493. The reversal of 256635490 is 94536652.

It can be written as a sum of positive squares in 4 ways, for example, as 240467049 + 16168441 = 15507^2 + 4021^2 .

It is not an unprimeable number, because it can be changed into a prime (256635493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31522 + ... + 38818.

Almost surely, 2^256635490 is an apocalyptic number.

256635490 is a deficient number, since it is larger than the sum of its proper divisors (205503062).

256635490 is a wasteful number, since it uses less digits than its factorization.

256635490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10821.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 256635490 is about 16019.8467533245. The cubic root of 256635490 is about 635.4853915788.

The spelling of 256635490 in words is "two hundred fifty-six million, six hundred thirty-five thousand, four hundred ninety".