81237975195 has 128 divisors (see below), whose sum is σ = 152467660800. Its totient is φ = 36578304000.

The previous prime is 81237975193. The next prime is 81237975199. The reversal of 81237975195 is 59157973218.

It is not a de Polignac number, because 81237975195 - 2¹ = 81237975193 is a prime.

It is a super-2 number, since 2×81237975195² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (81237975193) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 80512851 + ... + 80513859.

It is an arithmetic number, because the mean of its divisors is an integer number (1191153600).

Almost surely, 2^81237975195 is an apocalyptic number.

81237975195 is a deficient number, since it is larger than the sum of its proper divisors (71229685605).

81237975195 is a wasteful number, since it uses less digits than its factorization.

81237975195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781.

The product of its digits is 4762800, while the sum is 57.

The spelling of 81237975195 in words is "eighty-one billion, two hundred thirty-seven million, nine hundred seventy-five thousand, one hundred ninety-five".