91772880 has 80 divisors (see below), whose sum is σ = 285517440. Its totient is φ = 24385024.

The previous prime is 91772873. The next prime is 91772887. The reversal of 91772880 is 8827719.

It is an interprime number because it is at equal distance from previous prime (91772873) and next prime (91772887).

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91772887) 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, 92869 + ... + 93851.

It is an arithmetic number, because the mean of its divisors is an integer number (3568968).

Almost surely, 2^91772880 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 91772880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142758720).

91772880 is an abundant number, since it is smaller than the sum of its proper divisors (193744560).

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

91772880 is a wasteful number, since it uses less digits than its factorization.

91772880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388 (or 1382 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 91772880 is about 9579.8162821632. The cubic root of 91772880 is about 451.0639516132.

The spelling of 91772880 in words is "ninety-one million, seven hundred seventy-two thousand, eight hundred eighty".