72919891 has 32 divisors (see below), whose sum is σ = 88646400. Its totient is φ = 59230080.

The previous prime is 72919877. The next prime is 72919897. The reversal of 72919891 is 19891927.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 72919891 - 2¹⁵ = 72887123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72919897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 321120 + ... + 321346.

It is an arithmetic number, because the mean of its divisors is an integer number (2770200).

Almost surely, 2^72919891 is an apocalyptic number.

72919891 is a deficient number, since it is larger than the sum of its proper divisors (15726509).

72919891 is a wasteful number, since it uses less digits than its factorization.

72919891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339.

The product of its digits is 81648, while the sum is 46.

The square root of 72919891 is about 8539.3144338407. The cubic root of 72919891 is about 417.7809857443.

The spelling of 72919891 in words is "seventy-two million, nine hundred nineteen thousand, eight hundred ninety-one".