72186521 has 8 divisors (see below), whose sum is σ = 79005888. Its totient is φ = 65410000.

The previous prime is 72186509. The next prime is 72186523. The reversal of 72186521 is 12568127.

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 72186521 - 2²² = 67992217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72186523) 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, 7130 + ... + 13971.

It is an arithmetic number, because the mean of its divisors is an integer number (9875736).

Almost surely, 2^72186521 is an apocalyptic number.

It is an amenable number.

72186521 is a deficient number, since it is larger than the sum of its proper divisors (6819367).

72186521 is a wasteful number, since it uses less digits than its factorization.

72186521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21423.

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

The square root of 72186521 is about 8496.2651206280. The cubic root of 72186521 is about 416.3756949502.

The spelling of 72186521 in words is "seventy-two million, one hundred eighty-six thousand, five hundred twenty-one".