842000209 has 2 divisors, whose sum is σ = 842000210. Its totient is φ = 842000208.

The previous prime is 842000179. The next prime is 842000251. The reversal of 842000209 is 902000248.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 479478609 + 362521600 = 21897^2 + 19040^2 .

It is a cyclic number.

It is not a de Polignac number, because 842000209 - 2²⁵ = 808445777 is a prime.

It is not a weakly prime, because it can be changed into another prime (842000279) 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 as a sum of consecutive naturals, namely, 421000104 + 421000105.

It is an arithmetic number, because the mean of its divisors is an integer number (421000105).

Almost surely, 2^842000209 is an apocalyptic number.

It is an amenable number.

842000209 is a deficient number, since it is larger than the sum of its proper divisors (1).

842000209 is an equidigital number, since it uses as much as digits as its factorization.

842000209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 842000209 is about 29017.2398584014. The cubic root of 842000209 is about 944.2871209747.

The spelling of 842000209 in words is "eight hundred forty-two million, two hundred nine", and thus it is an aban number.