91975589 has 2 divisors, whose sum is σ = 91975590. Its totient is φ = 91975588.

The previous prime is 91975577. The next prime is 91975591. The reversal of 91975589 is 98557919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84953089 + 7022500 = 9217^2 + 2650^2 .

It is a cyclic number.

It is not a de Polignac number, because 91975589 - 2¹² = 91971493 is a prime.

Together with 91975591, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91975589.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91975529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45987794 + 45987795.

It is an arithmetic number, because the mean of its divisors is an integer number (45987795).

Almost surely, 2^91975589 is an apocalyptic number.

It is an amenable number.

91975589 is a deficient number, since it is larger than the sum of its proper divisors (1).

91975589 is an equidigital number, since it uses as much as digits as its factorization.

91975589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1020600, while the sum is 53.

The square root of 91975589 is about 9590.3904508628. The cubic root of 91975589 is about 451.3958124867.

The spelling of 91975589 in words is "ninety-one million, nine hundred seventy-five thousand, five hundred eighty-nine".