91977956576 has 96 divisors (see below), whose sum is σ = 199706744160. Its totient is φ = 41351731200.

The previous prime is 91977956573. The next prime is 91977956591. The reversal of 91977956576 is 67565977919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91977956573) 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, 25973366 + ... + 25976906.

It is an arithmetic number, because the mean of its divisors is an integer number (2080278585).

Almost surely, 2^91977956576 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 91977956576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99853372080).

91977956576 is an abundant number, since it is smaller than the sum of its proper divisors (107728787584).

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

91977956576 is a wasteful number, since it uses less digits than its factorization.

91977956576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4348 (or 4340 counting only the distinct ones).

The product of its digits is 225042300, while the sum is 71.

The spelling of 91977956576 in words is "ninety-one billion, nine hundred seventy-seven million, nine hundred fifty-six thousand, five hundred seventy-six".