991950 has 48 divisors (see below), whose sum is σ = 2611440. Its totient is φ = 248320.

The previous prime is 991943. The next prime is 991951. The reversal of 991950 is 59199.

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 991950.

It is not an unprimeable number, because it can be changed into a prime (991951) by changing a digit.

991950 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2356 + ... + 2744.

It is an arithmetic number, because the mean of its divisors is an integer number (54405).

2⁹⁹¹⁹⁵⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1305720).

991950 is an abundant number, since it is smaller than the sum of its proper divisors (1619490).

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

991950 is a wasteful number, since it uses less digits than its factorization.

991950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421 (or 416 counting only the distinct ones).

The product of its (nonzero) digits is 3645, while the sum is 33.

The square root of 991950 is about 995.9668669188. The cubic root of 991950 is about 99.7309434014.

The spelling of 991950 in words is "nine hundred ninety-one thousand, nine hundred fifty".