91557742320 has 240 divisors, whose sum is σ = 335742511104. Its totient is φ = 22175424000.

The previous prime is 91557742313. The next prime is 91557742321. The reversal of 91557742320 is 2324775519.

It is a happy number.

91557742320 is a `hidden beast` number, since 9 + 1 + 5 + 577 + 42 + 32 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91557742321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9744825 + ... + 9754215.

Almost surely, 2^91557742320 is an apocalyptic number.

91557742320 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 91557742320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167871255552).

91557742320 is an abundant number, since it is smaller than the sum of its proper divisors (244184768784).

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

91557742320 is a wasteful number, since it uses less digits than its factorization.

91557742320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10652 (or 10643 counting only the distinct ones).

The product of its (nonzero) digits is 529200, while the sum is 45.

The spelling of 91557742320 in words is "ninety-one billion, five hundred fifty-seven million, seven hundred forty-two thousand, three hundred twenty".