991886 has 8 divisors (see below), whose sum is σ = 1700400. Its totient is φ = 425088.

The previous prime is 991883. The next prime is 991889. The reversal of 991886 is 688199.

991886 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (991883) and next prime (991889).

It is a sphenic number, since it is the product of 3 distinct primes.

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 991886.

It is not an unprimeable number, because it can be changed into a prime (991883) 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, 35411 + ... + 35438.

It is an arithmetic number, because the mean of its divisors is an integer number (212550).

2⁹⁹¹⁸⁸⁶ is an apocalyptic number.

991886 is a deficient number, since it is larger than the sum of its proper divisors (708514).

991886 is a wasteful number, since it uses less digits than its factorization.

991886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70858.

The product of its digits is 31104, while the sum is 41.

The square root of 991886 is about 995.9347368176. The cubic root of 991886 is about 99.7287984957.

The spelling of 991886 in words is "nine hundred ninety-one thousand, eight hundred eighty-six".