91131870240 has 288 divisors, whose sum is σ = 320286461040. Its totient is φ = 23578877952.

The previous prime is 91131870223. The next prime is 91131870251. The reversal of 91131870240 is 4207813119.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 46237040784 + 44894829456 = 215028^2 + 211884^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 91131870195 and 91131870204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20723722 + ... + 20728118.

Almost surely, 2^91131870240 is an apocalyptic number.

91131870240 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 91131870240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160143230520).

91131870240 is an abundant number, since it is smaller than the sum of its proper divisors (229154590800).

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

91131870240 is a wasteful number, since it uses less digits than its factorization.

91131870240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4844 (or 4833 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The spelling of 91131870240 in words is "ninety-one billion, one hundred thirty-one million, eight hundred seventy thousand, two hundred forty".