991941432 has 128 divisors (see below), whose sum is σ = 2694954240. Its totient is φ = 303114240.

The previous prime is 991941427. The next prime is 991941437. The reversal of 991941432 is 234149199.

It is an interprime number because it is at equal distance from previous prime (991941427) and next prime (991941437).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991941437) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3580878 + ... + 3581154.

It is an arithmetic number, because the mean of its divisors is an integer number (21054330).

Almost surely, 2^991941432 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991941432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1347477120).

991941432 is an abundant number, since it is smaller than the sum of its proper divisors (1703012808).

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

991941432 is a wasteful number, since it uses less digits than its factorization.

991941432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501 (or 497 counting only the distinct ones).

The product of its digits is 69984, while the sum is 42.

The square root of 991941432 is about 31495.1017143936. The cubic root of 991941432 is about 997.3065625748.

The spelling of 991941432 in words is "nine hundred ninety-one million, nine hundred forty-one thousand, four hundred thirty-two".