91913820 has 24 divisors (see below), whose sum is σ = 257358864. Its totient is φ = 24510336.

The previous prime is 91913797. The next prime is 91913821. The reversal of 91913820 is 2831919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91913821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 765889 + ... + 766008.

It is an arithmetic number, because the mean of its divisors is an integer number (10723286).

Almost surely, 2^91913820 is an apocalyptic number.

It is an amenable number.

91913820 is an abundant number, since it is smaller than the sum of its proper divisors (165445044).

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

91913820 is a wasteful number, since it uses less digits than its factorization.

91913820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1531909 (or 1531907 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 91913820 is about 9587.1695510197. The cubic root of 91913820 is about 451.2947403352.

The spelling of 91913820 in words is "ninety-one million, nine hundred thirteen thousand, eight hundred twenty".