91291972 has 24 divisors (see below), whose sum is σ = 170753184. Its totient is φ = 42556032.

The previous prime is 91291961. The next prime is 91291973. The reversal of 91291972 is 27919219.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (91291973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1003 + ... + 13549.

It is an arithmetic number, because the mean of its divisors is an integer number (7114716).

Almost surely, 2^91291972 is an apocalyptic number.

It is an amenable number.

91291972 is a deficient number, since it is larger than the sum of its proper divisors (79461212).

91291972 is a wasteful number, since it uses less digits than its factorization.

91291972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12675 (or 12673 counting only the distinct ones).

The product of its digits is 20412, while the sum is 40.

The square root of 91291972 is about 9554.6832495902. The cubic root of 91291972 is about 450.2746833260.

The spelling of 91291972 in words is "ninety-one million, two hundred ninety-one thousand, nine hundred seventy-two".