256947990 has 32 divisors (see below), whose sum is σ = 664112736. Its totient is φ = 63248640.

The previous prime is 256947961. The next prime is 256948061. The reversal of 256947990 is 99749652.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 329031 + ... + 329810.

It is an arithmetic number, because the mean of its divisors is an integer number (20753523).

Almost surely, 2^256947990 is an apocalyptic number.

256947990 is an abundant number, since it is smaller than the sum of its proper divisors (407164746).

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

256947990 is a wasteful number, since it uses less digits than its factorization.

256947990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658864.

The product of its (nonzero) digits is 1224720, while the sum is 51.

The square root of 256947990 is about 16029.5973124717. The cubic root of 256947990 is about 635.7432263173.

The spelling of 256947990 in words is "two hundred fifty-six million, nine hundred forty-seven thousand, nine hundred ninety".