1998887 has 4 divisors (see below), whose sum is σ = 2180616. Its totient is φ = 1817160.

The previous prime is 1998881. The next prime is 1998917. The reversal of 1998887 is 7888991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998881) 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, 90848 + ... + 90869.

It is an arithmetic number, because the mean of its divisors is an integer number (545154).

2^1998887 is an apocalyptic number.

1998887 is a deficient number, since it is larger than the sum of its proper divisors (181729).

1998887 is a wasteful number, since it uses less digits than its factorization.

1998887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181728.

The product of its digits is 290304, while the sum is 50.

The square root of 1998887 is about 1413.8200026878. The cubic root of 1998887 is about 125.9687291173.

The spelling of 1998887 in words is "one million, nine hundred ninety-eight thousand, eight hundred eighty-seven".