72117442121 has 16 divisors (see below), whose sum is σ = 75096806400. Its totient is φ = 69171916800.

The previous prime is 72117442097. The next prime is 72117442147. The reversal of 72117442121 is 12124471127.

It is a cyclic number.

It is not a de Polignac number, because 72117442121 - 2³⁰ = 71043700297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72117442021) 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, 4251026 + ... + 4267956.

It is an arithmetic number, because the mean of its divisors is an integer number (4693550400).

Almost surely, 2^72117442121 is an apocalyptic number.

It is an amenable number.

72117442121 is a deficient number, since it is larger than the sum of its proper divisors (2979364279).

72117442121 is a wasteful number, since it uses less digits than its factorization.

72117442121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17920.

The product of its digits is 6272, while the sum is 32.

The spelling of 72117442121 in words is "seventy-two billion, one hundred seventeen million, four hundred forty-two thousand, one hundred twenty-one".