72165217 has 4 divisors (see below), whose sum is σ = 72228016. Its totient is φ = 72102420.

The previous prime is 72165131. The next prime is 72165229. The reversal of 72165217 is 71256127.

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 72165217 - 2⁷ = 72165089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72160217) 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, 29643 + ... + 31984.

It is an arithmetic number, because the mean of its divisors is an integer number (18057004).

Almost surely, 2^72165217 is an apocalyptic number.

It is an amenable number.

72165217 is a deficient number, since it is larger than the sum of its proper divisors (62799).

72165217 is a wasteful number, since it uses less digits than its factorization.

72165217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62798.

The product of its digits is 5880, while the sum is 31.

The square root of 72165217 is about 8495.0113007576. The cubic root of 72165217 is about 416.3347300514.

The spelling of 72165217 in words is "seventy-two million, one hundred sixty-five thousand, two hundred seventeen".