91861399782 has 32 divisors (see below), whose sum is σ = 204169759200. Its totient is φ = 30615469344.

The previous prime is 91861399781. The next prime is 91861399811. The reversal of 91861399782 is 28799316819.

91861399782 is a `hidden beast` number, since 9 + 1 + 8 + 613 + 9 + 9 + 7 + 8 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91861399781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 202848 + ... + 474204.

It is an arithmetic number, because the mean of its divisors is an integer number (6380304975).

Almost surely, 2^91861399782 is an apocalyptic number.

91861399782 is an abundant number, since it is smaller than the sum of its proper divisors (112308359418).

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

91861399782 is a wasteful number, since it uses less digits than its factorization.

91861399782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277637 (or 277631 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 63.

The spelling of 91861399782 in words is "ninety-one billion, eight hundred sixty-one million, three hundred ninety-nine thousand, seven hundred eighty-two".