209485140209 has 2 divisors, whose sum is σ = 209485140210. Its totient is φ = 209485140208.

The previous prime is 209485140197. The next prime is 209485140229. The reversal of 209485140209 is 902041584902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167489655025 + 41995485184 = 409255^2 + 204928^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209485140209 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 209485140209.

It is not a weakly prime, because it can be changed into another prime (209485140229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104742570104 + 104742570105.

It is an arithmetic number, because the mean of its divisors is an integer number (104742570105).

Almost surely, 2^209485140209 is an apocalyptic number.

It is an amenable number.

209485140209 is a deficient number, since it is larger than the sum of its proper divisors (1).

209485140209 is an equidigital number, since it uses as much as digits as its factorization.

209485140209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 44.

The spelling of 209485140209 in words is "two hundred nine billion, four hundred eighty-five million, one hundred forty thousand, two hundred nine".