1998331 has 2 divisors, whose sum is σ = 1998332. Its totient is φ = 1998330.

The previous prime is 1998329. The next prime is 1998341. The reversal of 1998331 is 1338991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1998331 - 2¹ = 1998329 is a prime.

It is a super-2 number, since 2×1998331² = 7986653571122, which contains 22 as substring.

Together with 1998329, it forms a pair of twin primes.

1998331 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1998301) by changing a digit.

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, 999165 + 999166.

It is an arithmetic number, because the mean of its divisors is an integer number (999166).

2^1998331 is an apocalyptic number.

1998331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998331 is an equidigital number, since it uses as much as digits as its factorization.

1998331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 34.

The square root of 1998331 is about 1413.6233586072. The cubic root of 1998331 is about 125.9570484322.

The spelling of 1998331 in words is "one million, nine hundred ninety-eight thousand, three hundred thirty-one".