72166515723 has 12 divisors (see below), whose sum is σ = 105036253608. Its totient is φ = 47743750080.

The previous prime is 72166515713. The next prime is 72166515763. The reversal of 72166515723 is 32751566127.

It is a happy number.

72166515723 is a `hidden beast` number, since 7 + 2 + 1 + 66 + 515 + 72 + 3 = 666.

It is not a de Polignac number, because 72166515723 - 2⁸ = 72166515467 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (72166515713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30603790 + ... + 30606147.

It is an arithmetic number, because the mean of its divisors is an integer number (8753021134).

Almost surely, 2^72166515723 is an apocalyptic number.

72166515723 is a deficient number, since it is larger than the sum of its proper divisors (32869737885).

72166515723 is a wasteful number, since it uses less digits than its factorization.

72166515723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61210074 (or 61210071 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The spelling of 72166515723 in words is "seventy-two billion, one hundred sixty-six million, five hundred fifteen thousand, seven hundred twenty-three".