991081982 has 8 divisors (see below), whose sum is σ = 1621770552. Its totient is φ = 450491800.

The previous prime is 991081979. The next prime is 991081991. The reversal of 991081982 is 289180199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a pancake number, because a pancake can be divided into 991081982 parts by 44521 straight cuts.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22524569 + ... + 22524612.

It is an arithmetic number, because the mean of its divisors is an integer number (202721319).

Almost surely, 2^991081982 is an apocalyptic number.

991081982 is a deficient number, since it is larger than the sum of its proper divisors (630688570).

991081982 is a wasteful number, since it uses less digits than its factorization.

991081982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45049194.

The product of its (nonzero) digits is 93312, while the sum is 47.

The square root of 991081982 is about 31481.4545724939. The cubic root of 991081982 is about 997.0184465071.

The spelling of 991081982 in words is "nine hundred ninety-one million, eighty-one thousand, nine hundred eighty-two".