72165218 has 8 divisors (see below), whose sum is σ = 108292140. Its totient is φ = 36067840.

The previous prime is 72165131. The next prime is 72165229. The reversal of 72165218 is 81256127.

It can be written as a sum of positive squares in 2 ways, for example, as 67683529 + 4481689 = 8227^2 + 2117^2 .

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

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338 + ... + 12018.

Almost surely, 2^72165218 is an apocalyptic number.

72165218 is a deficient number, since it is larger than the sum of its proper divisors (36126922).

72165218 is a wasteful number, since it uses less digits than its factorization.

72165218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14772.

The product of its digits is 6720, while the sum is 32.

The square root of 72165218 is about 8495.0113596157. The cubic root of 72165218 is about 416.3347319745.

Subtracting 72165218 from its reverse (81256127), we obtain a palindrome (9090909).

The spelling of 72165218 in words is "seventy-two million, one hundred sixty-five thousand, two hundred eighteen".