842209 has 2 divisors, whose sum is σ = 842210. Its totient is φ = 842208.

The previous prime is 842203. The next prime is 842249. The reversal of 842209 is 902248.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 451584 + 390625 = 672^2 + 625^2 .

It is a cyclic number.

It is not a de Polignac number, because 842209 - 2⁷ = 842081 is a prime.

842209 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (842203) by changing a digit.

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 as a sum of consecutive naturals, namely, 421104 + 421105.

It is an arithmetic number, because the mean of its divisors is an integer number (421105).

2⁸⁴²²⁰⁹ is an apocalyptic number.

It is an amenable number.

842209 is a deficient number, since it is larger than the sum of its proper divisors (1).

842209 is an equidigital number, since it uses as much as digits as its factorization.

842209 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 842209 is about 917.7194560431. The cubic root of 842209 is about 94.4365166228.

The spelling of 842209 in words is "eight hundred forty-two thousand, two hundred nine".