72311972 has 6 divisors (see below), whose sum is σ = 126545958. Its totient is φ = 36155984.

The previous prime is 72311971. The next prime is 72311989. The reversal of 72311972 is 27911327.

It can be written as a sum of positive squares in only one way, i.e., 53787556 + 18524416 = 7334^2 + 4304^2 .

It is not an unprimeable number, because it can be changed into a prime (72311971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9038993 + ... + 9039000.

It is an arithmetic number, because the mean of its divisors is an integer number (21090993).

Almost surely, 2^72311972 is an apocalyptic number.

It is an amenable number.

72311972 is a deficient number, since it is larger than the sum of its proper divisors (54233986).

72311972 is a wasteful number, since it uses less digits than its factorization.

72311972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18077997 (or 18077995 counting only the distinct ones).

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

The square root of 72311972 is about 8503.6446303923. The cubic root of 72311972 is about 416.6167580399.

The spelling of 72311972 in words is "seventy-two million, three hundred eleven thousand, nine hundred seventy-two".