991041137760 has 384 divisors, whose sum is σ = 3440840933376. Its totient is φ = 238940190720.

The previous prime is 991041137743. The next prime is 991041137833. The reversal of 991041137760 is 67731140199.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14682649 + ... + 14749991.

It is an arithmetic number, because the mean of its divisors is an integer number (8960523264).

Almost surely, 2^991041137760 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 991041137760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1720420466688).

991041137760 is an abundant number, since it is smaller than the sum of its proper divisors (2449799795616).

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

991041137760 is a wasteful number, since it uses less digits than its factorization.

991041137760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67458 (or 67450 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 48.

The spelling of 991041137760 in words is "nine hundred ninety-one billion, forty-one million, one hundred thirty-seven thousand, seven hundred sixty".