91391976 has 160 divisors (see below), whose sum is σ = 290690400. Its totient is φ = 26593920.

The previous prime is 91391959. The next prime is 91391977. The reversal of 91391976 is 67919319.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (91391977) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 159771 + ... + 160341.

It is an arithmetic number, because the mean of its divisors is an integer number (1816815).

Almost surely, 2^91391976 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 91391976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145345200).

91391976 is an abundant number, since it is smaller than the sum of its proper divisors (199298424).

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

91391976 is a wasteful number, since it uses less digits than its factorization.

91391976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621 (or 608 counting only the distinct ones).

The product of its digits is 91854, while the sum is 45.

The square root of 91391976 is about 9559.9150623842. The cubic root of 91391976 is about 450.4390381840.

The spelling of 91391976 in words is "ninety-one million, three hundred ninety-one thousand, nine hundred seventy-six".