72217081 has 16 divisors (see below), whose sum is σ = 79921600. Its totient is φ = 64991808.

The previous prime is 72217069. The next prime is 72217087. The reversal of 72217081 is 18071227.

It is a cyclic number.

It is not a de Polignac number, because 72217081 - 2⁷ = 72216953 is a prime.

It is a super-2 number, since 2×72217081² = 10430613576321122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72217087) 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, 29035 + ... + 31423.

It is an arithmetic number, because the mean of its divisors is an integer number (4995100).

Almost surely, 2^72217081 is an apocalyptic number.

It is an amenable number.

72217081 is a deficient number, since it is larger than the sum of its proper divisors (7704519).

72217081 is a wasteful number, since it uses less digits than its factorization.

72217081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2488.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 72217081 is about 8498.0633676150. The cubic root of 72217081 is about 416.4344438960.

The spelling of 72217081 in words is "seventy-two million, two hundred seventeen thousand, eighty-one".