991441972 has 24 divisors (see below), whose sum is σ = 1859227776. Its totient is φ = 460937088.

The previous prime is 991441961. The next prime is 991441987. The reversal of 991441972 is 279144199.

It is a congruent number.

It is an unprimeable number.

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, 82188 + ... + 93475.

It is an arithmetic number, because the mean of its divisors is an integer number (77467824).

Almost surely, 2^991441972 is an apocalyptic number.

It is an amenable number.

991441972 is a deficient number, since it is larger than the sum of its proper divisors (867785804).

991441972 is a wasteful number, since it uses less digits than its factorization.

991441972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175767 (or 175765 counting only the distinct ones).

The product of its digits is 163296, while the sum is 46.

The square root of 991441972 is about 31487.1715465203. The cubic root of 991441972 is about 997.1391473268.

It can be divided in two parts, 99144197 and 2, that added together give a palindrome (99144199).

The spelling of 991441972 in words is "nine hundred ninety-one million, four hundred forty-one thousand, nine hundred seventy-two".