91939393 has 16 divisors (see below), whose sum is σ = 113747200. Its totient is φ = 72363456.

The previous prime is 91939381. The next prime is 91939409. The reversal of 91939393 is 39393919.

It is a cyclic number.

It is not a de Polignac number, because 91939393 - 2⁵ = 91939361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91939373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15571 + ... + 20647.

It is an arithmetic number, because the mean of its divisors is an integer number (7109200).

Almost surely, 2^91939393 is an apocalyptic number.

It is an amenable number.

91939393 is a deficient number, since it is larger than the sum of its proper divisors (21807807).

91939393 is a wasteful number, since it uses less digits than its factorization.

91939393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5296.

The product of its digits is 177147, while the sum is 46.

The square root of 91939393 is about 9588.5031678568. The cubic root of 91939393 is about 451.3365907346.

The spelling of 91939393 in words is "ninety-one million, nine hundred thirty-nine thousand, three hundred ninety-three".