1998718 has 4 divisors (see below), whose sum is σ = 2998080. Its totient is φ = 999358.

The previous prime is 1998701. The next prime is 1998727. The reversal of 1998718 is 8178991.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499678 + ... + 499681.

It is an arithmetic number, because the mean of its divisors is an integer number (749520).

2^1998718 is an apocalyptic number.

1998718 is a deficient number, since it is larger than the sum of its proper divisors (999362).

1998718 is an equidigital number, since it uses as much as digits as its factorization.

1998718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999361.

The product of its digits is 36288, while the sum is 43.

The square root of 1998718 is about 1413.7602342689. The cubic root of 1998718 is about 125.9651789224.

The spelling of 1998718 in words is "one million, nine hundred ninety-eight thousand, seven hundred eighteen".