72999121 has 16 divisors (see below), whose sum is σ = 83059200. Its totient is φ = 63600768.

The previous prime is 72999109. The next prime is 72999137. The reversal of 72999121 is 12199927.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 72999121 - 2⁵ = 72999089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72999161) 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, 118005 + ... + 118621.

It is an arithmetic number, because the mean of its divisors is an integer number (5191200).

Almost surely, 2^72999121 is an apocalyptic number.

It is an amenable number.

72999121 is a deficient number, since it is larger than the sum of its proper divisors (10060079).

72999121 is a wasteful number, since it uses less digits than its factorization.

72999121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128.

The product of its digits is 20412, while the sum is 40.

The square root of 72999121 is about 8543.9523055785. The cubic root of 72999121 is about 417.9322421706.

The spelling of 72999121 in words is "seventy-two million, nine hundred ninety-nine thousand, one hundred twenty-one".