91000987918720 has 320 divisors, whose sum is σ = 240774830161200. Its totient is φ = 32887702425600.

The previous prime is 91000987918717. The next prime is 91000987918721. The reversal of 91000987918720 is 2781978900019.

It is a tau number, because it is divible by the number of its divisors (320).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91000987918721) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 1527319330 + ... + 1527378910.

Almost surely, 2^{91000987918720} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91000987918720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120387415080600).

91000987918720 is an abundant number, since it is smaller than the sum of its proper divisors (149773842242480).

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

91000987918720 is an equidigital number, since it uses as much as digits as its factorization.

91000987918720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59807 (or 59762 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 61.

The spelling of 91000987918720 in words is "ninety-one trillion, nine hundred eighty-seven million, nine hundred eighteen thousand, seven hundred twenty".