91398875904 has 360 divisors, whose sum is σ = 322223600160. Its totient is φ = 25212321792.

The previous prime is 91398875903. The next prime is 91398875951. The reversal of 91398875904 is 40957889319.

91398875904 is a `hidden beast` number, since 9 + 1 + 39 + 8 + 8 + 7 + 590 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (91398875903) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4198552 + ... + 4220264.

It is an arithmetic number, because the mean of its divisors is an integer number (895065556).

Almost surely, 2^91398875904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91398875904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161111800080).

91398875904 is an abundant number, since it is smaller than the sum of its proper divisors (230824724256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91398875904 is a wasteful number, since it uses less digits than its factorization.

91398875904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21777 (or 21754 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 63.

The spelling of 91398875904 in words is "ninety-one billion, three hundred ninety-eight million, eight hundred seventy-five thousand, nine hundred four".