991309976 has 32 divisors (see below), whose sum is σ = 1893672000. Its totient is φ = 486362016.

The previous prime is 991309973. The next prime is 991309981. The reversal of 991309976 is 679903199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991309973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309455 + ... + 312641.

It is an arithmetic number, because the mean of its divisors is an integer number (59177250).

Almost surely, 2^991309976 is an apocalyptic number.

It is an amenable number.

991309976 is a deficient number, since it is larger than the sum of its proper divisors (902362024).

991309976 is a wasteful number, since it uses less digits than its factorization.

991309976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3911 (or 3907 counting only the distinct ones).

The product of its (nonzero) digits is 826686, while the sum is 53.

The square root of 991309976 is about 31485.0754485359. The cubic root of 991309976 is about 997.0948938644.

The spelling of 991309976 in words is "nine hundred ninety-one million, three hundred nine thousand, nine hundred seventy-six".