91163761920 has 648 divisors, whose sum is σ = 396268873728. Its totient is φ = 18941091840.

The previous prime is 91163761879. The next prime is 91163761963. The reversal of 91163761920 is 2916736119.

91163761920 is a `hidden beast` number, since 9 + 1 + 1 + 6 + 3 + 7 + 619 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 9752769 + ... + 9762111.

Almost surely, 2^91163761920 is an apocalyptic number.

91163761920 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 91163761920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198134436864).

91163761920 is an abundant number, since it is smaller than the sum of its proper divisors (305105111808).

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

91163761920 is a wasteful number, since it uses less digits than its factorization.

91163761920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9399 (or 9371 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 45.

The spelling of 91163761920 in words is "ninety-one billion, one hundred sixty-three million, seven hundred sixty-one thousand, nine hundred twenty".