72197697931 has 4 divisors (see below), whose sum is σ = 72288285552. Its totient is φ = 72107110312.

The previous prime is 72197697917. The next prime is 72197697977. The reversal of 72197697931 is 13979679127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13979679127 = 83 ⋅168429869.

It is a cyclic number.

It is not a de Polignac number, because 72197697931 - 2²⁹ = 71660827019 is a prime.

It is a super-2 number, since 2×72197697931² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72197697931.

It is not an unprimeable number, because it can be changed into a prime (72197697631) 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, 45292615 + ... + 45294208.

It is an arithmetic number, because the mean of its divisors is an integer number (18072071388).

Almost surely, 2^72197697931 is an apocalyptic number.

72197697931 is a deficient number, since it is larger than the sum of its proper divisors (90587621).

72197697931 is an equidigital number, since it uses as much as digits as its factorization.

72197697931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90587620.

The product of its digits is 9001692, while the sum is 61.

The spelling of 72197697931 in words is "seventy-two billion, one hundred ninety-seven million, six hundred ninety-seven thousand, nine hundred thirty-one".