991796208 has 80 divisors (see below), whose sum is σ = 2811382560. Its totient is φ = 299400192.

The previous prime is 991796173. The next prime is 991796233. The reversal of 991796208 is 802697199.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18078 + ... + 48066.

It is an arithmetic number, because the mean of its divisors is an integer number (35142282).

Almost surely, 2^991796208 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 991796208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1405691280).

991796208 is an abundant number, since it is smaller than the sum of its proper divisors (1819586352).

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

991796208 is a wasteful number, since it uses less digits than its factorization.

991796208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30066 (or 30060 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 51.

The square root of 991796208 is about 31492.7961286387. The cubic root of 991796208 is about 997.2578903743.

The spelling of 991796208 in words is "nine hundred ninety-one million, seven hundred ninety-six thousand, two hundred eight".