1005209 has 2 divisors, whose sum is σ = 1005210. Its totient is φ = 1005208.

The previous prime is 1005203. The next prime is 1005217. The reversal of 1005209 is 9025001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 931225 + 73984 = 965^2 + 272^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005209 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (1005203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502604 + 502605.

It is an arithmetic number, because the mean of its divisors is an integer number (502605).

2^1005209 is an apocalyptic number.

It is an amenable number.

1005209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005209 is an equidigital number, since it uses as much as digits as its factorization.

1005209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 1005209 is about 1002.6011170949. The cubic root of 1005209 is about 100.1733327174.

The spelling of 1005209 in words is "one million, five thousand, two hundred nine".