72217631 has 8 divisors (see below), whose sum is σ = 77789184. Its totient is φ = 66848760.

The previous prime is 72217619. The next prime is 72217633. The reversal of 72217631 is 13671227.

72217631 = T₂₁₄₃ + T₂₁₄₄ + ... + T₂₁₇₃.

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 72217631 - 2¹⁸ = 71955487 is a prime.

It is a super-2 number, since 2×72217631² = 10430772454504322, 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 = 72217594 and 72217603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72217633) 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, 49931 + ... + 51356.

It is an arithmetic number, because the mean of its divisors is an integer number (9723648).

Almost surely, 2^72217631 is an apocalyptic number.

72217631 is a deficient number, since it is larger than the sum of its proper divisors (5571553).

72217631 is a wasteful number, since it uses less digits than its factorization.

72217631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101341.

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

The square root of 72217631 is about 8498.0957278675. The cubic root of 72217631 is about 416.4355010714.

Adding to 72217631 its reverse (13671227), we get a palindrome (85888858).

The spelling of 72217631 in words is "seventy-two million, two hundred seventeen thousand, six hundred thirty-one".