81361624172 has 12 divisors (see below), whose sum is σ = 142385146176. Its totient is φ = 40680153840.

The previous prime is 81361624129. The next prime is 81361624237. The reversal of 81361624172 is 27142616318.

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, 206522 + ... + 453182.

It is an arithmetic number, because the mean of its divisors is an integer number (11865428848).

Almost surely, 2^81361624172 is an apocalyptic number.

It is an amenable number.

81361624172 is a deficient number, since it is larger than the sum of its proper divisors (61023522004).

81361624172 is a wasteful number, since it uses less digits than its factorization.

81361624172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329128 (or 329126 counting only the distinct ones).

The product of its digits is 96768, while the sum is 41.

The spelling of 81361624172 in words is "eighty-one billion, three hundred sixty-one million, six hundred twenty-four thousand, one hundred seventy-two".