991870110 has 512 divisors, whose sum is σ = 3627417600. Its totient is φ = 188956800.

The previous prime is 991870097. The next prime is 991870153. The reversal of 991870110 is 11078199.

It is a super-2 number, since 2×991870110² = 1967612630222824200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 31995795 + ... + 31995825.

It is an arithmetic number, because the mean of its divisors is an integer number (7084800).

Almost surely, 2^991870110 is an apocalyptic number.

991870110 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 991870110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1813708800).

991870110 is an abundant number, since it is smaller than the sum of its proper divisors (2635547490).

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

991870110 is a wasteful number, since it uses less digits than its factorization.

991870110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 36.

The square root of 991870110 is about 31493.9694227323. The cubic root of 991870110 is about 997.2826594150.

The spelling of 991870110 in words is "nine hundred ninety-one million, eight hundred seventy thousand, one hundred ten".