91981722 has 24 divisors (see below), whose sum is σ = 213998976. Its totient is φ = 26280408.

The previous prime is 91981709. The next prime is 91981753. The reversal of 91981722 is 22718919.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 156138 + ... + 156725.

It is an arithmetic number, because the mean of its divisors is an integer number (8916624).

Almost surely, 2^91981722 is an apocalyptic number.

91981722 is an abundant number, since it is smaller than the sum of its proper divisors (122017254).

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

91981722 is a wasteful number, since it uses less digits than its factorization.

91981722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312882 (or 312875 counting only the distinct ones).

The product of its digits is 18144, while the sum is 39.

The square root of 91981722 is about 9590.7101926812. The cubic root of 91981722 is about 451.4058453988.

The spelling of 91981722 in words is "ninety-one million, nine hundred eighty-one thousand, seven hundred twenty-two".