1998841 has 4 divisors (see below), whose sum is σ = 2152612. Its totient is φ = 1845072.

The previous prime is 1998839. The next prime is 1998881. The reversal of 1998841 is 1488991.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1040400 + 958441 = 1020^2 + 979^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998841 - 2¹ = 1998839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1998794 and 1998803.

It is not an unprimeable number, because it can be changed into a prime (1998881) 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 in 3 ways as a sum of consecutive naturals, for example, 76866 + ... + 76891.

It is an arithmetic number, because the mean of its divisors is an integer number (538153).

2^1998841 is an apocalyptic number.

It is an amenable number.

1998841 is a deficient number, since it is larger than the sum of its proper divisors (153771).

1998841 is a wasteful number, since it uses less digits than its factorization.

1998841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153770.

The product of its digits is 20736, while the sum is 40.

The square root of 1998841 is about 1413.8037346110. The cubic root of 1998841 is about 125.9677628118.

The spelling of 1998841 in words is "one million, nine hundred ninety-eight thousand, eight hundred forty-one".