1998998 has 4 divisors (see below), whose sum is σ = 2998500. Its totient is φ = 999498.

The previous prime is 1998991. The next prime is 1999007. The reversal of 1998998 is 8998991.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499748 + ... + 499751.

It is an arithmetic number, because the mean of its divisors is an integer number (749625).

2^1998998 is an apocalyptic number.

1998998 is a deficient number, since it is larger than the sum of its proper divisors (999502).

1998998 is an equidigital number, since it uses as much as digits as its factorization.

1998998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999501.

The product of its digits is 419904, while the sum is 53.

The square root of 1998998 is about 1413.8592574935. The cubic root of 1998998 is about 125.9710607932.

The spelling of 1998998 in words is "one million, nine hundred ninety-eight thousand, nine hundred ninety-eight".