991903776 has 96 divisors (see below), whose sum is σ = 2722406400. Its totient is φ = 315843840.

The previous prime is 991903763. The next prime is 991903813. The reversal of 991903776 is 677309199.

It is a tau number, because it is divible by the number of its divisors (96).

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, 232995 + ... + 237213.

It is an arithmetic number, because the mean of its divisors is an integer number (28358400).

Almost surely, 2^991903776 is an apocalyptic number.

991903776 is a gapful number since it is divisible by the number (96) 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 991903776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1361203200).

991903776 is an abundant number, since it is smaller than the sum of its proper divisors (1730502624).

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

991903776 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (991903775) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (4334).

991903776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4342 (or 4334 counting only the distinct ones).

The product of its (nonzero) digits is 642978, while the sum is 51.

The square root of 991903776 is about 31494.5039014746. The cubic root of 991903776 is about 997.2939425249.

The spelling of 991903776 in words is "nine hundred ninety-one million, nine hundred three thousand, seven hundred seventy-six".