991936 has 28 divisors (see below), whose sum is σ = 2148840. Its totient is φ = 450560.

The previous prime is 991931. The next prime is 991943. The reversal of 991936 is 639199.

991936 is a nontrivial binomial coefficient, being equal to C(1409, 2).

It is a junction number, because it is equal to n+sod(n) for n = 991895 and 991904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 1408.

2⁹⁹¹⁹³⁶ is an apocalyptic number.

991936 is the 1408-th triangular number.

991936 is the 470-th centered nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1074420).

991936 is an abundant number, since it is smaller than the sum of its proper divisors (1156904).

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

991936 is a wasteful number, since it uses less digits than its factorization.

991936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1432 (or 1422 counting only the distinct ones).

The product of its digits is 13122, while the sum is 37.

The square root of 991936 is about 995.9598385477. The cubic root of 991936 is about 99.7304742111.

It can be divided in two parts, 99193 and 6, that added together give a palindrome (99199).

The spelling of 991936 in words is "nine hundred ninety-one thousand, nine hundred thirty-six".