72189990 has 96 divisors (see below), whose sum is σ = 205714080. Its totient is φ = 17482752.

The previous prime is 72189989. The next prime is 72190003. The reversal of 72189990 is 9998127.

It is a super-2 number, since 2×72189990² = 10422789312400200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 43557 + ... + 45183.

It is an arithmetic number, because the mean of its divisors is an integer number (2142855).

Almost surely, 2^72189990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72189990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102857040).

72189990 is an abundant number, since it is smaller than the sum of its proper divisors (133524090).

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

72189990 is a wasteful number, since it uses less digits than its factorization.

72189990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1686 (or 1683 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 72189990 is about 8496.4692667013. The cubic root of 72189990 is about 416.3823646356.

The spelling of 72189990 in words is "seventy-two million, one hundred eighty-nine thousand, nine hundred ninety".