1998985 has 8 divisors (see below), whose sum is σ = 2407176. Its totient is φ = 1593600.

The previous prime is 1998977. The next prime is 1998991. The reversal of 1998985 is 5898991.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1159929 + 839056 = 1077^2 + 916^2 .

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

It is not a de Polignac number, because 1998985 - 2³ = 1998977 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 1507 + ... + 2503.

It is an arithmetic number, because the mean of its divisors is an integer number (300897).

2^1998985 is an apocalyptic number.

It is an amenable number.

1998985 is a deficient number, since it is larger than the sum of its proper divisors (408191).

1998985 is an equidigital number, since it uses as much as digits as its factorization.

1998985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1403.

The product of its digits is 233280, while the sum is 49.

The square root of 1998985 is about 1413.8546601401. The cubic root of 1998985 is about 125.9707877185.

The spelling of 1998985 in words is "one million, nine hundred ninety-eight thousand, nine hundred eighty-five".