72312615 has 64 divisors (see below), whose sum is σ = 136581120. Its totient is φ = 36236160.

The previous prime is 72312601. The next prime is 72312619. The reversal of 72312615 is 51621327.

It is a happy number.

It is not a de Polignac number, because 72312615 - 2⁶ = 72312551 is a prime.

It is a super-2 number, since 2×72312615² = 10458228576276450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72312619) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 154612 + ... + 155078.

It is an arithmetic number, because the mean of its divisors is an integer number (2134080).

Almost surely, 2^72312615 is an apocalyptic number.

72312615 is a deficient number, since it is larger than the sum of its proper divisors (64268505).

72312615 is a wasteful number, since it uses less digits than its factorization.

72312615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549 (or 543 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 72312615 is about 8503.6824376267. The cubic root of 72312615 is about 416.6179928921.

It can be divided in two parts, 72312 and 615, that added together give a palindrome (72927).

The spelling of 72312615 in words is "seventy-two million, three hundred twelve thousand, six hundred fifteen".