72312131 has 4 divisors (see below), whose sum is σ = 72864264. Its totient is φ = 71760000.

The previous prime is 72312127. The next prime is 72312137. The reversal of 72312131 is 13121327.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72312131 - 2² = 72312127 is a prime.

It is a super-2 number, since 2×72312131² = 10458088579522322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72312137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 275870 + ... + 276131.

It is an arithmetic number, because the mean of its divisors is an integer number (18216066).

Almost surely, 2^72312131 is an apocalyptic number.

72312131 is a deficient number, since it is larger than the sum of its proper divisors (552133).

72312131 is a wasteful number, since it uses less digits than its factorization.

72312131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552132.

The product of its digits is 252, while the sum is 20.

The square root of 72312131 is about 8503.6539793197. The cubic root of 72312131 is about 416.6170633928.

Adding to 72312131 its reverse (13121327), we get a palindrome (85433458).

The spelling of 72312131 in words is "seventy-two million, three hundred twelve thousand, one hundred thirty-one".