139286209 has 2 divisors, whose sum is σ = 139286210. Its totient is φ = 139286208.

The previous prime is 139286153. The next prime is 139286227. The reversal of 139286209 is 902682931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124099600 + 15186609 = 11140^2 + 3897^2 .

It is an emirp because it is prime and its reverse (902682931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139286209 - 2¹⁵ = 139253441 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139286299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69643104 + 69643105.

It is an arithmetic number, because the mean of its divisors is an integer number (69643105).

Almost surely, 2^139286209 is an apocalyptic number.

It is an amenable number.

139286209 is a deficient number, since it is larger than the sum of its proper divisors (1).

139286209 is an equidigital number, since it uses as much as digits as its factorization.

139286209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 139286209 is about 11801.9578460525. The cubic root of 139286209 is about 518.3654405612.

The spelling of 139286209 in words is "one hundred thirty-nine million, two hundred eighty-six thousand, two hundred nine".