991820712960 has 3696 divisors, whose sum is σ = 4958372115360. Its totient is φ = 187280916480.

The previous prime is 991820712937. The next prime is 991820713001. The reversal of 991820712960 is 69217028199.

It is a tau number, because it is divible by the number of its divisors (3696).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 991820712897 and 991820712906.

It is an unprimeable number.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 34200714226 + ... + 34200714254.

Almost surely, 2^991820712960 is an apocalyptic number.

991820712960 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 991820712960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2479186057680).

991820712960 is an abundant number, since it is smaller than the sum of its proper divisors (3966551402400).

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

991820712960 is a wasteful number, since it uses less digits than its factorization.

991820712960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The spelling of 991820712960 in words is "nine hundred ninety-one billion, eight hundred twenty million, seven hundred twelve thousand, nine hundred sixty".