72165631 has 8 divisors (see below), whose sum is σ = 73465920. Its totient is φ = 70875168.

The previous prime is 72165581. The next prime is 72165637. The reversal of 72165631 is 13656127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72165631 - 2¹³ = 72157439 is a prime.

It is a super-2 number, since 2×72165631² = 10415756595256322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72165593 and 72165602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72165637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13245 + ... + 17881.

It is an arithmetic number, because the mean of its divisors is an integer number (9183240).

Almost surely, 2^72165631 is an apocalyptic number.

72165631 is a deficient number, since it is larger than the sum of its proper divisors (1300289).

72165631 is a wasteful number, since it uses less digits than its factorization.

72165631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4913.

The product of its digits is 7560, while the sum is 31.

The square root of 72165631 is about 8495.0356679651. The cubic root of 72165631 is about 416.3355261979.

The spelling of 72165631 in words is "seventy-two million, one hundred sixty-five thousand, six hundred thirty-one".