91993878369 has 48 divisors (see below), whose sum is σ = 137751164928. Its totient is φ = 59113587456.

The previous prime is 91993878359. The next prime is 91993878401. The reversal of 91993878369 is 96387839919.

It is a happy number.

91993878369 is a `hidden beast` number, since 9 + 199 + 3 + 8 + 78 + 369 = 666.

It is not a de Polignac number, because 91993878369 - 2³⁵ = 57634140001 is a prime.

It is a super-2 number, since 2×91993878369² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91993878297 and 91993878306.

It is not an unprimeable number, because it can be changed into a prime (91993878359) 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 47 ways as a sum of consecutive naturals, for example, 40048429 + ... + 40050725.

It is an arithmetic number, because the mean of its divisors is an integer number (2869815936).

Almost surely, 2^91993878369 is an apocalyptic number.

It is an amenable number.

91993878369 is a deficient number, since it is larger than the sum of its proper divisors (45757286559).

91993878369 is a wasteful number, since it uses less digits than its factorization.

91993878369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3414 (or 3411 counting only the distinct ones).

The product of its digits is 158723712, while the sum is 72.

The spelling of 91993878369 in words is "ninety-one billion, nine hundred ninety-three million, eight hundred seventy-eight thousand, three hundred sixty-nine".