991168 has 28 divisors (see below), whose sum is σ = 2084832. Its totient is φ = 465920.

The previous prime is 991147. The next prime is 991171. The reversal of 991168 is 861199.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

991168 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 3 ways as a sum of consecutive naturals, for example, 633 + ... + 1543.

2⁹⁹¹¹⁶⁸ 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 991168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1042416).

991168 is an abundant number, since it is smaller than the sum of its proper divisors (1093664).

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

991168 is a wasteful number, since it uses less digits than its factorization.

991168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940 (or 930 counting only the distinct ones).

The product of its digits is 3888, while the sum is 34.

The square root of 991168 is about 995.5742061745. The cubic root of 991168 is about 99.7047290085.

The spelling of 991168 in words is "nine hundred ninety-one thousand, one hundred sixty-eight".