72184221 has 12 divisors (see below), whose sum is σ = 104427648. Its totient is φ = 48048264.

The previous prime is 72184207. The next prime is 72184223. The reversal of 72184221 is 12248127.

It is not a de Polignac number, because 72184221 - 2⁶ = 72184157 is a prime.

It is a super-2 number, since 2×72184221² = 10421123522753682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72184223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 276 + ... + 12018.

It is an arithmetic number, because the mean of its divisors is an integer number (8702304).

Almost surely, 2^72184221 is an apocalyptic number.

It is an amenable number.

72184221 is a deficient number, since it is larger than the sum of its proper divisors (32243427).

72184221 is a wasteful number, since it uses less digits than its factorization.

72184221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12432 (or 12429 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 72184221 is about 8496.1297659581. The cubic root of 72184221 is about 416.3712727291.

The spelling of 72184221 in words is "seventy-two million, one hundred eighty-four thousand, two hundred twenty-one".