991143232 has 56 divisors (see below), whose sum is σ = 2066544000. Its totient is φ = 470739456.

The previous prime is 991143229. The next prime is 991143239. The reversal of 991143232 is 232341199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991143239) 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, 217069 + ... + 221587.

Almost surely, 2^991143232 is an apocalyptic number.

991143232 is a gapful number since it is divisible by the number (92) 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 991143232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1033272000).

991143232 is an abundant number, since it is smaller than the sum of its proper divisors (1075400768).

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

991143232 is a wasteful number, since it uses less digits than its factorization.

991143232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4703 (or 4693 counting only the distinct ones).

The product of its digits is 11664, while the sum is 34.

The square root of 991143232 is about 31482.4273524136. The cubic root of 991143232 is about 997.0389850441.

The spelling of 991143232 in words is "nine hundred ninety-one million, one hundred forty-three thousand, two hundred thirty-two".