91171895880 has 128 divisors (see below), whose sum is σ = 296675164800. Its totient is φ = 22280804352.

The previous prime is 91171895873. The next prime is 91171895921. The reversal of 91171895880 is 8859817119.

It is a self number, because there is not a number n which added to its sum of digits gives 91171895880.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6612 + ... + 427068.

It is an arithmetic number, because the mean of its divisors is an integer number (2317774725).

Almost surely, 2^91171895880 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 91171895880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148337582400).

91171895880 is an abundant number, since it is smaller than the sum of its proper divisors (205503268920).

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

91171895880 is a wasteful number, since it uses less digits than its factorization.

91171895880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420623 (or 420619 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 57.

The spelling of 91171895880 in words is "ninety-one billion, one hundred seventy-one million, eight hundred ninety-five thousand, eight hundred eighty".