72217581 has 8 divisors (see below), whose sum is σ = 101954304. Its totient is φ = 45312960.

The previous prime is 72217577. The next prime is 72217591. The reversal of 72217581 is 18571227.

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

It is not a de Polignac number, because 72217581 - 2² = 72217577 is a prime.

It is a super-2 number, since 2×72217581² = 10430758010983122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72217531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 707965 + ... + 708066.

It is an arithmetic number, because the mean of its divisors is an integer number (12744288).

Almost surely, 2^72217581 is an apocalyptic number.

It is an amenable number.

72217581 is a deficient number, since it is larger than the sum of its proper divisors (29736723).

72217581 is a wasteful number, since it uses less digits than its factorization.

72217581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416051.

The product of its digits is 7840, while the sum is 33.

The square root of 72217581 is about 8498.0927860315. The cubic root of 72217581 is about 416.4354049648.

The spelling of 72217581 in words is "seventy-two million, two hundred seventeen thousand, five hundred eighty-one".