256561892 has 24 divisors (see below), whose sum is σ = 477463896. Its totient is φ = 120209408.

The previous prime is 256561873. The next prime is 256561897. The reversal of 256561892 is 298165652.

It can be written as a sum of positive squares in 4 ways, for example, as 109327936 + 147233956 = 10456^2 + 12134^2 .

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (256561897) 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, 7748 + ... + 23940.

It is an arithmetic number, because the mean of its divisors is an integer number (19894329).

Almost surely, 2^256561892 is an apocalyptic number.

It is an amenable number.

256561892 is a deficient number, since it is larger than the sum of its proper divisors (220902004).

256561892 is a wasteful number, since it uses less digits than its factorization.

256561892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16447 (or 16445 counting only the distinct ones).

The product of its digits is 259200, while the sum is 44.

The square root of 256561892 is about 16017.5495004698. The cubic root of 256561892 is about 635.4246375427.

The spelling of 256561892 in words is "two hundred fifty-six million, five hundred sixty-one thousand, eight hundred ninety-two".