72216081631 has 16 divisors (see below), whose sum is σ = 73309350400. Its totient is φ = 71131737600.

The previous prime is 72216081601. The next prime is 72216081647. The reversal of 72216081631 is 13618061227.

It is a 9-Lehmer number, since φ(72216081631) divides (72216081631-1)⁹.

It is a cyclic number.

It is not a de Polignac number, because 72216081631 - 2²³ = 72207693023 is a prime.

It is a super-2 number, since 2×72216081631² (a number of 23 digits) contains 22 as substring.

It is the 268731-st Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72216081601) by changing a digit.

It is a nontrivial repunit in base 268730.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17361730 + ... + 17365888.

It is an arithmetic number, because the mean of its divisors is an integer number (4581834400).

Almost surely, 2^72216081631 is an apocalyptic number.

72216081631 is a deficient number, since it is larger than the sum of its proper divisors (1093268769).

72216081631 is a wasteful number, since it uses less digits than its factorization.

72216081631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5170.

The product of its (nonzero) digits is 24192, while the sum is 37.

The spelling of 72216081631 in words is "seventy-two billion, two hundred sixteen million, eighty-one thousand, six hundred thirty-one".