72321638631 has 16 divisors (see below), whose sum is σ = 105379367808. Its totient is φ = 43754522400.

The previous prime is 72321638617. The next prime is 72321638651. The reversal of 72321638631 is 13683612327.

It is a de Polignac number, because none of the positive numbers 2^k-72321638631 is a prime.

It is a super-2 number, since 2×72321638631² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72321638651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1900216 + ... + 1937901.

It is an arithmetic number, because the mean of its divisors is an integer number (6586210488).

Almost surely, 2^72321638631 is an apocalyptic number.

72321638631 is a deficient number, since it is larger than the sum of its proper divisors (33057729177).

72321638631 is a wasteful number, since it uses less digits than its factorization.

72321638631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3838702.

The product of its digits is 217728, while the sum is 42.

The spelling of 72321638631 in words is "seventy-two billion, three hundred twenty-one million, six hundred thirty-eight thousand, six hundred thirty-one".