81431938934 has 32 divisors (see below), whose sum is σ = 127368430560. Its totient is φ = 39022627072.

The previous prime is 81431938933. The next prime is 81431938943. The reversal of 81431938934 is 43983913418.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81431938933) 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, 731024 + ... + 835020.

It is an arithmetic number, because the mean of its divisors is an integer number (3980263455).

Almost surely, 2^81431938934 is an apocalyptic number.

81431938934 is a deficient number, since it is larger than the sum of its proper divisors (45936491626).

81431938934 is a wasteful number, since it uses less digits than its factorization.

81431938934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104224.

The product of its digits is 2239488, while the sum is 53.

The spelling of 81431938934 in words is "eighty-one billion, four hundred thirty-one million, nine hundred thirty-eight thousand, nine hundred thirty-four".