72188864 has 84 divisors (see below), whose sum is σ = 162802824. Its totient is φ = 31488000.

The previous prime is 72188843. The next prime is 72188869. The reversal of 72188864 is 46888127.

It is a super-2 number, since 2×72188864² = 10422464171220992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72188869) 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, 1183394 + ... + 1183454.

Almost surely, 2^72188864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72188864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81401412).

72188864 is an abundant number, since it is smaller than the sum of its proper divisors (90613960).

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

72188864 is a wasteful number, since it uses less digits than its factorization.

72188864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 115 counting only the distinct ones).

The product of its digits is 172032, while the sum is 44.

The square root of 72188864 is about 8496.4030036245. The cubic root of 72188864 is about 416.3801997510.

The spelling of 72188864 in words is "seventy-two million, one hundred eighty-eight thousand, eight hundred sixty-four".