72972131 has 4 divisors (see below), whose sum is σ = 73015512. Its totient is φ = 72928752.

The previous prime is 72972127. The next prime is 72972157. The reversal of 72972131 is 13127927.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13127927 = 17 ⋅772231.

It is a cyclic number.

It is not a de Polignac number, because 72972131 - 2² = 72972127 is a prime.

It is a super-2 number, since 2×72972131² = 10649863805362322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72971131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19061 + ... + 22566.

It is an arithmetic number, because the mean of its divisors is an integer number (18253878).

Almost surely, 2^72972131 is an apocalyptic number.

72972131 is a deficient number, since it is larger than the sum of its proper divisors (43381).

72972131 is a wasteful number, since it uses less digits than its factorization.

72972131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43380.

The product of its digits is 5292, while the sum is 32.

The square root of 72972131 is about 8542.3726797653. The cubic root of 72972131 is about 417.8807283919.

The spelling of 72972131 in words is "seventy-two million, nine hundred seventy-two thousand, one hundred thirty-one".