91651321580 has 96 divisors (see below), whose sum is σ = 237721795584. Its totient is φ = 28903474944.

The previous prime is 91651321453. The next prime is 91651321673. The reversal of 91651321580 is 8512315619.

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, 426089 + ... + 604031.

It is an arithmetic number, because the mean of its divisors is an integer number (2476268704).

Almost surely, 2^91651321580 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 91651321580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118860897792).

91651321580 is an abundant number, since it is smaller than the sum of its proper divisors (146070474004).

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

91651321580 is a wasteful number, since it uses less digits than its factorization.

91651321580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178255 (or 178253 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 41.

The spelling of 91651321580 in words is "ninety-one billion, six hundred fifty-one million, three hundred twenty-one thousand, five hundred eighty".