91989243 has 16 divisors (see below), whose sum is σ = 137815200. Its totient is φ = 60635520.

The previous prime is 91989223. The next prime is 91989251. The reversal of 91989243 is 34298919.

It is not a de Polignac number, because 91989243 - 2⁵ = 91989211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91989223) 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, 16738 + ... + 21543.

It is an arithmetic number, because the mean of its divisors is an integer number (8613450).

Almost surely, 2^91989243 is an apocalyptic number.

91989243 is a deficient number, since it is larger than the sum of its proper divisors (45825957).

91989243 is a wasteful number, since it uses less digits than its factorization.

91989243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38379 (or 38373 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 91989243 is about 9591.1022828453. The cubic root of 91989243 is about 451.4181483171.

The spelling of 91989243 in words is "ninety-one million, nine hundred eighty-nine thousand, two hundred forty-three".