991303983 has 48 divisors (see below), whose sum is σ = 1569728160. Its totient is φ = 600348672.

The previous prime is 991303909. The next prime is 991303987. The reversal of 991303983 is 389303199.

It is not a de Polignac number, because 991303983 - 2⁸ = 991303727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991303987) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 584685 + ... + 586377.

It is an arithmetic number, because the mean of its divisors is an integer number (32702670).

Almost surely, 2^991303983 is an apocalyptic number.

991303983 is a deficient number, since it is larger than the sum of its proper divisors (578424177).

991303983 is a wasteful number, since it uses less digits than its factorization.

991303983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1848 (or 1845 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The square root of 991303983 is about 31484.9802763159. The cubic root of 991303983 is about 997.0928845360.

The spelling of 991303983 in words is "nine hundred ninety-one million, three hundred three thousand, nine hundred eighty-three".