1999859 has 2 divisors, whose sum is σ = 1999860. Its totient is φ = 1999858.

The previous prime is 1999853. The next prime is 1999867. The reversal of 1999859 is 9589991.

It is a weak prime.

It is an emirp because it is prime and its reverse (9589991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1999859 - 2⁸ = 1999603 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1999853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999929 + 999930.

It is an arithmetic number, because the mean of its divisors is an integer number (999930).

2^1999859 is an apocalyptic number.

1999859 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999859 is an equidigital number, since it uses as much as digits as its factorization.

1999859 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 262440, while the sum is 50.

The square root of 1999859 is about 1414.1637104664. The cubic root of 1999859 is about 125.9891441054.

The spelling of 1999859 in words is "one million, nine hundred ninety-nine thousand, eight hundred fifty-nine".