1998839 has 2 divisors, whose sum is σ = 1998840. Its totient is φ = 1998838.

The previous prime is 1998827. The next prime is 1998881. The reversal of 1998839 is 9388991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1998839 - 2¹² = 1994743 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1998793 and 1998802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999419 + 999420.

It is an arithmetic number, because the mean of its divisors is an integer number (999420).

2^1998839 is an apocalyptic number.

1998839 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998839 is an equidigital number, since it uses as much as digits as its factorization.

1998839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 47.

The square root of 1998839 is about 1413.8030272991. The cubic root of 1998839 is about 125.9677207982.

The spelling of 1998839 in words is "one million, nine hundred ninety-eight thousand, eight hundred thirty-nine".