1998031 has 4 divisors (see below), whose sum is σ = 2283472. Its totient is φ = 1712592.

The previous prime is 1998023. The next prime is 1998041. The reversal of 1998031 is 1308991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1308991 = 829 ⋅1579.

It is not a de Polignac number, because 1998031 - 2³ = 1998023 is a prime.

It is a super-2 number, since 2×1998031² = 7984255753922, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 1997984 and 1998002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142710 + ... + 142723.

It is an arithmetic number, because the mean of its divisors is an integer number (570868).

2^1998031 is an apocalyptic number.

1998031 is a deficient number, since it is larger than the sum of its proper divisors (285441).

1998031 is an equidigital number, since it uses as much as digits as its factorization.

1998031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285440.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 1998031 is about 1413.5172443235. The cubic root of 1998031 is about 125.9507450044.

The spelling of 1998031 in words is "one million, nine hundred ninety-eight thousand, thirty-one".