1331561256 has 16 divisors (see below), whose sum is σ = 3328903200. Its totient is φ = 443853744.

The previous prime is 1331561243. The next prime is 1331561269. The reversal of 1331561256 is 6521651331.

It is an interprime number because it is at equal distance from previous prime (1331561243) and next prime (1331561269).

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, 27740836 + ... + 27740883.

It is an arithmetic number, because the mean of its divisors is an integer number (208056450).

Almost surely, 2^1331561256 is an apocalyptic number.

It is an amenable number.

1331561256 is an abundant number, since it is smaller than the sum of its proper divisors (1997341944).

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

1331561256 is a wasteful number, since it uses less digits than its factorization.

1331561256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55481728 (or 55481724 counting only the distinct ones).

The product of its digits is 16200, while the sum is 33.

The square root of 1331561256 is about 36490.5639309671. The cubic root of 1331561256 is about 1100.1545942502.

The spelling of 1331561256 in words is "one billion, three hundred thirty-one million, five hundred sixty-one thousand, two hundred fifty-six".