991632 has 40 divisors (see below), whose sum is σ = 2605984. Its totient is φ = 324864.

The previous prime is 991621. The next prime is 991633. The reversal of 991632 is 236199.

It is a self number, because there is not a number n which added to its sum of digits gives 991632.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991632.

It is not an unprimeable number, because it can be changed into a prime (991633) by changing a digit.

991632 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3363 + ... + 3645.

2⁹⁹¹⁶³² 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 991632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1302992).

991632 is an abundant number, since it is smaller than the sum of its proper divisors (1614352).

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

991632 is a wasteful number, since it uses less digits than its factorization.

991632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367 (or 361 counting only the distinct ones).

The product of its digits is 2916, while the sum is 30.

The square root of 991632 is about 995.8072102571. The cubic root of 991632 is about 99.7202849913.

The spelling of 991632 in words is "nine hundred ninety-one thousand, six hundred thirty-two".