1998144 has 42 divisors (see below), whose sum is σ = 5728970. Its totient is φ = 665856.

The previous prime is 1998133. The next prime is 1998169. The reversal of 1998144 is 4418991.

It can be written as a sum of positive squares in only one way, i.e., 1166400 + 831744 = 1080^2 + 912^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1998099 and 1998108.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1159 + ... + 2310.

2^1998144 is an apocalyptic number.

It is an amenable number.

1998144 is an abundant number, since it is smaller than the sum of its proper divisors (3730826).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1998144 is a wasteful number, since it uses less digits than its factorization.

1998144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3487 (or 3474 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 1998144 is about 1413.5572149722. The cubic root of 1998144 is about 125.9531193696.

The spelling of 1998144 in words is "one million, nine hundred ninety-eight thousand, one hundred forty-four".