1311643881 has 16 divisors (see below), whose sum is σ = 1943734720. Its totient is φ = 874177920.

The previous prime is 1311643843. The next prime is 1311643939. The reversal of 1311643881 is 1883461131.

1311643881 is a `hidden beast` number, since 1 + 3 + 1 + 1 + 643 + 8 + 8 + 1 = 666.

It is not a de Polignac number, because 1311643881 - 2²⁷ = 1177426153 is a prime.

It is a super-2 number, since 2×1311643881² = 3440819341129484322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311643181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 173721 + ... + 181113.

It is an arithmetic number, because the mean of its divisors is an integer number (121483420).

Almost surely, 2^1311643881 is an apocalyptic number.

It is an amenable number.

1311643881 is a deficient number, since it is larger than the sum of its proper divisors (632090839).

1311643881 is an equidigital number, since it uses as much as digits as its factorization.

1311643881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13973 (or 13967 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1311643881 is about 36216.6243733455. The cubic root of 1311643881 is about 1094.6416767141.

The spelling of 1311643881 in words is "one billion, three hundred eleven million, six hundred forty-three thousand, eight hundred eighty-one".