91998923 has 2 divisors, whose sum is σ = 91998924. Its totient is φ = 91998922.

The previous prime is 91998913. The next prime is 91998947. The reversal of 91998923 is 32989919.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91998923 - 2⁶ = 91998859 is a prime.

It is not a weakly prime, because it can be changed into another prime (91998913) 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, 45999461 + 45999462.

It is an arithmetic number, because the mean of its divisors is an integer number (45999462).

Almost surely, 2^91998923 is an apocalyptic number.

91998923 is a deficient number, since it is larger than the sum of its proper divisors (1).

91998923 is an equidigital number, since it uses as much as digits as its factorization.

91998923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 50.

The square root of 91998923 is about 9591.6069039551. The cubic root of 91998923 is about 451.4339819597.

The spelling of 91998923 in words is "ninety-one million, nine hundred ninety-eight thousand, nine hundred twenty-three".