256561516 has 12 divisors (see below), whose sum is σ = 449143240. Its totient is φ = 128234880.

The previous prime is 256561507. The next prime is 256561537. The reversal of 256561516 is 615165652.

It is a super-2 number, since 2×256561516² = 131647622984436512, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3196 + ... + 22876.

Almost surely, 2^256561516 is an apocalyptic number.

It is an amenable number.

256561516 is a deficient number, since it is larger than the sum of its proper divisors (192581724).

256561516 is a wasteful number, since it uses less digits than its factorization.

256561516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22944 (or 22942 counting only the distinct ones).

The product of its digits is 54000, while the sum is 37.

The square root of 256561516 is about 16017.5377633393. The cubic root of 256561516 is about 635.4243271306.

It can be divided in two parts, 25656 and 1516, that added together give a palindrome (27172).

The spelling of 256561516 in words is "two hundred fifty-six million, five hundred sixty-one thousand, five hundred sixteen".