72191990 has 32 divisors (see below), whose sum is σ = 140918400. Its totient is φ = 26469504.

The previous prime is 72191983. The next prime is 72191993. The reversal of 72191990 is 9919127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72191993) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17507 + ... + 21233.

It is an arithmetic number, because the mean of its divisors is an integer number (4403700).

Almost surely, 2^72191990 is an apocalyptic number.

72191990 is a deficient number, since it is larger than the sum of its proper divisors (68726410).

72191990 is a wasteful number, since it uses less digits than its factorization.

72191990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3896.

The product of its (nonzero) digits is 10206, while the sum is 38.

The square root of 72191990 is about 8496.5869618336. The cubic root of 72191990 is about 416.3862098457.

The spelling of 72191990 in words is "seventy-two million, one hundred ninety-one thousand, nine hundred ninety".