81122125929 has 16 divisors (see below), whose sum is σ = 117791856000. Its totient is φ = 49360392576.

The previous prime is 81122125891. The next prime is 81122125949. The reversal of 81122125929 is 92952122118.

It is not a de Polignac number, because 81122125929 - 2⁸ = 81122125673 is a prime.

It is a super-2 number, since 2×81122125929² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81122125949) 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, 11682229 + ... + 11689170.

It is an arithmetic number, because the mean of its divisors is an integer number (7361991000).

Almost surely, 2^81122125929 is an apocalyptic number.

81122125929 is a gapful number since it is divisible by the number (89) formed by its first and last digit.

It is an amenable number.

81122125929 is a deficient number, since it is larger than the sum of its proper divisors (36669730071).

81122125929 is a wasteful number, since it uses less digits than its factorization.

81122125929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23371504.

The product of its digits is 51840, while the sum is 42.

The spelling of 81122125929 in words is "eighty-one billion, one hundred twenty-two million, one hundred twenty-five thousand, nine hundred twenty-nine".