91355171281920 has 3168 divisors, whose sum is σ = 404168610553344. Its totient is φ = 18673945804800.

The previous prime is 91355171281873. The next prime is 91355171281937. The reversal of 91355171281920 is 2918217155319.

91355171281920 is a `hidden beast` number, since 9 + 1 + 3 + 551 + 7 + 1 + 2 + 81 + 9 + 2 + 0 = 666.

91355171281920 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×91355171281920² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 275997496155 + ... + 275997496485.

Almost surely, 2^{91355171281920} is an apocalyptic number.

91355171281920 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 91355171281920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202084305276672).

91355171281920 is an abundant number, since it is smaller than the sum of its proper divisors (312813439271424).

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

91355171281920 is a wasteful number, since it uses less digits than its factorization.

91355171281920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539 (or 505 counting only the distinct ones).

The product of its (nonzero) digits is 1360800, while the sum is 54.

The spelling of 91355171281920 in words is "ninety-one trillion, three hundred fifty-five billion, one hundred seventy-one million, two hundred eighty-one thousand, nine hundred twenty".