91998717 has 4 divisors (see below), whose sum is σ = 122664960. Its totient is φ = 61332476.

The previous prime is 91998691. The next prime is 91998727. The reversal of 91998717 is 71789919.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91998717 - 2⁶ = 91998653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91998717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91998727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15333117 + ... + 15333122.

It is an arithmetic number, because the mean of its divisors is an integer number (30666240).

Almost surely, 2^91998717 is an apocalyptic number.

It is an amenable number.

91998717 is a deficient number, since it is larger than the sum of its proper divisors (30666243).

91998717 is a wasteful number, since it uses less digits than its factorization.

91998717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30666242.

The product of its digits is 285768, while the sum is 51.

The square root of 91998717 is about 9591.5961653940. The cubic root of 91998717 is about 451.4336450157.

The spelling of 91998717 in words is "ninety-one million, nine hundred ninety-eight thousand, seven hundred seventeen".