91691750880 has 144 divisors (see below), whose sum is σ = 313115834304. Its totient is φ = 24434119680.

The previous prime is 91691750869. The next prime is 91691750921. The reversal of 91691750880 is 8805719619.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2119870 + ... + 2162690.

It is an arithmetic number, because the mean of its divisors is an integer number (2174415516).

Almost surely, 2^91691750880 is an apocalyptic number.

91691750880 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91691750880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156557917152).

91691750880 is an abundant number, since it is smaller than the sum of its proper divisors (221424083424).

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

91691750880 is a wasteful number, since it uses less digits than its factorization.

91691750880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44329 (or 44318 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 54.

The spelling of 91691750880 in words is "ninety-one billion, six hundred ninety-one million, seven hundred fifty thousand, eight hundred eighty".