91517879 has 2 divisors, whose sum is σ = 91517880. Its totient is φ = 91517878.

The previous prime is 91517857. The next prime is 91517887. The reversal of 91517879 is 97871519.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91517879 - 2²⁰ = 90469303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91517479) 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 as a sum of consecutive naturals, namely, 45758939 + 45758940.

It is an arithmetic number, because the mean of its divisors is an integer number (45758940).

Almost surely, 2^91517879 is an apocalyptic number.

91517879 is a deficient number, since it is larger than the sum of its proper divisors (1).

91517879 is an equidigital number, since it uses as much as digits as its factorization.

91517879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 47.

The square root of 91517879 is about 9566.4977395074. The cubic root of 91517879 is about 450.6457872019.

The spelling of 91517879 in words is "ninety-one million, five hundred seventeen thousand, eight hundred seventy-nine".