72217729 has 8 divisors (see below), whose sum is σ = 73344960. Its totient is φ = 71098896.

The previous prime is 72217679. The next prime is 72217741. The reversal of 72217729 is 92771227.

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 72217729 - 2⁷ = 72217601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72217129) 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, 16479 + ... + 20395.

It is an arithmetic number, because the mean of its divisors is an integer number (9168120).

Almost surely, 2^72217729 is an apocalyptic number.

It is an amenable number.

72217729 is a deficient number, since it is larger than the sum of its proper divisors (1127231).

72217729 is a wasteful number, since it uses less digits than its factorization.

72217729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4199.

The product of its digits is 24696, while the sum is 37.

The square root of 72217729 is about 8498.1014938632. The cubic root of 72217729 is about 416.4356894403.

The spelling of 72217729 in words is "seventy-two million, two hundred seventeen thousand, seven hundred twenty-nine".