1998123 has 4 divisors (see below), whose sum is σ = 2664168. Its totient is φ = 1332080.

The previous prime is 1998119. The next prime is 1998127. The reversal of 1998123 is 3218991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3218991 = 3 ⋅1072997.

It is an interprime number because it is at equal distance from previous prime (1998119) and next prime (1998127).

It is a cyclic number.

It is not a de Polignac number, because 1998123 - 2² = 1998119 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1998127) 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, 333018 + ... + 333023.

It is an arithmetic number, because the mean of its divisors is an integer number (666042).

2^1998123 is an apocalyptic number.

1998123 is a deficient number, since it is larger than the sum of its proper divisors (666045).

1998123 is an equidigital number, since it uses as much as digits as its factorization.

1998123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666044.

The product of its digits is 3888, while the sum is 33.

The square root of 1998123 is about 1413.5497868841. The cubic root of 1998123 is about 125.9526781227.

The spelling of 1998123 in words is "one million, nine hundred ninety-eight thousand, one hundred twenty-three".