1998243 has 16 divisors (see below), whose sum is σ = 3188640. Its totient is φ = 1229472.

The previous prime is 1998233. The next prime is 1998251. The reversal of 1998243 is 3428991.

It is not a de Polignac number, because 1998243 - 2⁹ = 1997731 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1998198 and 1998207.

It is not an unprimeable number, because it can be changed into a prime (1998223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2496 + ... + 3197.

It is an arithmetic number, because the mean of its divisors is an integer number (199290).

2^1998243 is an apocalyptic number.

1998243 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1998243 is a deficient number, since it is larger than the sum of its proper divisors (1190397).

1998243 is a wasteful number, since it uses less digits than its factorization.

1998243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5715 (or 5709 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 1998243 is about 1413.5922325763. The cubic root of 1998243 is about 125.9551994921.

The spelling of 1998243 in words is "one million, nine hundred ninety-eight thousand, two hundred forty-three".