1998855 has 24 divisors (see below), whose sum is σ = 3548688. Its totient is φ = 1040256.

The previous prime is 1998839. The next prime is 1998881. The reversal of 1998855 is 5588991.

It is not a de Polignac number, because 1998855 - 2⁴ = 1998839 is a prime.

It is a super-2 number, since 2×1998855² = 7990842622050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

1998855 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1998855.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1419 + ... + 2451.

It is an arithmetic number, because the mean of its divisors is an integer number (147862).

2^1998855 is an apocalyptic number.

1998855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1998855 is a deficient number, since it is larger than the sum of its proper divisors (1549833).

1998855 is a wasteful number, since it uses less digits than its factorization.

1998855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1087 (or 1084 counting only the distinct ones).

The product of its digits is 129600, while the sum is 45.

The square root of 1998855 is about 1413.8086857846. The cubic root of 1998855 is about 125.9680569064.

The spelling of 1998855 in words is "one million, nine hundred ninety-eight thousand, eight hundred fifty-five".