991898 has 8 divisors (see below), whose sum is σ = 1552608. Its totient is φ = 474364.

The previous prime is 991889. The next prime is 991901. The reversal of 991898 is 898199.

991898 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10736 + ... + 10827.

It is an arithmetic number, because the mean of its divisors is an integer number (194076).

2⁹⁹¹⁸⁹⁸ is an apocalyptic number.

991898 is a deficient number, since it is larger than the sum of its proper divisors (560710).

991898 is a wasteful number, since it uses less digits than its factorization.

991898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21588.

The product of its digits is 46656, while the sum is 44.

The square root of 991898 is about 995.9407612905. The cubic root of 991898 is about 99.7292006725.

The spelling of 991898 in words is "nine hundred ninety-one thousand, eight hundred ninety-eight".