72217517 has 4 divisors (see below), whose sum is σ = 72419040. Its totient is φ = 72015996.

The previous prime is 72217489. The next prime is 72217529. The reversal of 72217517 is 71571227.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72217517 - 2¹⁴ = 72201133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72217577) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100223 + ... + 100940.

It is an arithmetic number, because the mean of its divisors is an integer number (18104760).

Almost surely, 2^72217517 is an apocalyptic number.

It is an amenable number.

72217517 is a deficient number, since it is larger than the sum of its proper divisors (201523).

72217517 is a wasteful number, since it uses less digits than its factorization.

72217517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201522.

The product of its digits is 6860, while the sum is 32.

The square root of 72217517 is about 8498.0890204798. The cubic root of 72217517 is about 416.4352819482.

The spelling of 72217517 in words is "seventy-two million, two hundred seventeen thousand, five hundred seventeen".