1998668 has 24 divisors (see below), whose sum is σ = 4097184. Its totient is φ = 835200.

The previous prime is 1998643. The next prime is 1998679. The reversal of 1998668 is 8668991.

1998668 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 278 + ... + 2018.

It is an arithmetic number, because the mean of its divisors is an integer number (170716).

2^1998668 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 1998668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2048592).

1998668 is an abundant number, since it is smaller than the sum of its proper divisors (2098516).

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

1998668 is a wasteful number, since it uses less digits than its factorization.

1998668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1793 (or 1791 counting only the distinct ones).

The product of its digits is 186624, while the sum is 47.

The square root of 1998668 is about 1413.7425508203. The cubic root of 1998668 is about 125.9641285305.

The spelling of 1998668 in words is "one million, nine hundred ninety-eight thousand, six hundred sixty-eight".