72187812 has 36 divisors (see below), whose sum is σ = 183879696. Its totient is φ = 23877360.

The previous prime is 72187807. The next prime is 72187813. The reversal of 72187812 is 21878127.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×72187812² = 10422160402694688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is not an unprimeable number, because it can be changed into a prime (72187813) 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, 2938 + ... + 12369.

Almost surely, 2^72187812 is an apocalyptic number.

It is an amenable number.

72187812 is an abundant number, since it is smaller than the sum of its proper divisors (111691884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72187812 is a wasteful number, since it uses less digits than its factorization.

72187812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15448 (or 15443 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 72187812 is about 8496.3410948478. The cubic root of 72187812 is about 416.3781771210.

The spelling of 72187812 in words is "seventy-two million, one hundred eighty-seven thousand, eight hundred twelve".