72621731 has 16 divisors (see below), whose sum is σ = 89687808. Its totient is φ = 57261600.

The previous prime is 72621719. The next prime is 72621733. The reversal of 72621731 is 13712627.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72621731 is a prime.

It is a super-2 number, since 2×72621731² = 10547831626872722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72621694 and 72621703.

It is not an unprimeable number, because it can be changed into a prime (72621733) 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, 28916 + ... + 31326.

It is an arithmetic number, because the mean of its divisors is an integer number (5605488).

Almost surely, 2^72621731 is an apocalyptic number.

72621731 is a deficient number, since it is larger than the sum of its proper divisors (17066077).

72621731 is a wasteful number, since it uses less digits than its factorization.

72621731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2762.

The product of its digits is 3528, while the sum is 29.

The square root of 72621731 is about 8521.8384753526. The cubic root of 72621731 is about 417.2107904189.

The spelling of 72621731 in words is "seventy-two million, six hundred twenty-one thousand, seven hundred thirty-one".