91819768320 has 1280 divisors, whose sum is σ = 401254318080. Its totient is φ = 19444727808.

The previous prime is 91819768267. The next prime is 91819768333. The reversal of 91819768320 is 2386791819.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 411747729 + ... + 411747951.

It is an arithmetic number, because the mean of its divisors is an integer number (313479936).

Almost surely, 2^91819768320 is an apocalyptic number.

91819768320 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91819768320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200627159040).

91819768320 is an abundant number, since it is smaller than the sum of its proper divisors (309434549760).

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

91819768320 is a wasteful number, since it uses less digits than its factorization.

91819768320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 91819768320 in words is "ninety-one billion, eight hundred nineteen million, seven hundred sixty-eight thousand, three hundred twenty".