256406646 has 16 divisors (see below), whose sum is σ = 512999424. Its totient is φ = 85437864.

The previous prime is 256406639. The next prime is 256406663. The reversal of 256406646 is 646604652.

It is a super-2 number, since 2×256406646² = 131488736225938632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15535 + ... + 27461.

It is an arithmetic number, because the mean of its divisors is an integer number (32062464).

Almost surely, 2^256406646 is an apocalyptic number.

256406646 is an abundant number, since it is smaller than the sum of its proper divisors (256592778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256406646 is a wasteful number, since it uses less digits than its factorization.

256406646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15515.

The product of its (nonzero) digits is 207360, while the sum is 39.

The square root of 256406646 is about 16012.7026450877. The cubic root of 256406646 is about 635.2964462040.

The spelling of 256406646 in words is "two hundred fifty-six million, four hundred six thousand, six hundred forty-six".