81375224139 has 24 divisors (see below), whose sum is σ = 131209670592. Its totient is φ = 48171377520.

The previous prime is 81375224131. The next prime is 81375224141. The reversal of 81375224139 is 93142257318.

It is a happy number.

81375224139 is a `hidden beast` number, since 8 + 1 + 375 + 2 + 241 + 39 = 666.

It is not a de Polignac number, because 81375224139 - 2³ = 81375224131 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81375224094 and 81375224103.

It is not an unprimeable number, because it can be changed into a prime (81375224131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9553557 + ... + 9562070.

It is an arithmetic number, because the mean of its divisors is an integer number (5467069608).

Almost surely, 2^81375224139 is an apocalyptic number.

81375224139 is a deficient number, since it is larger than the sum of its proper divisors (49834446453).

81375224139 is a wasteful number, since it uses less digits than its factorization.

81375224139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19115687 (or 19115684 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The spelling of 81375224139 in words is "eighty-one billion, three hundred seventy-five million, two hundred twenty-four thousand, one hundred thirty-nine".