139259209 has 2 divisors, whose sum is σ = 139259210. Its totient is φ = 139259208.

The previous prime is 139259201. The next prime is 139259233. The reversal of 139259209 is 902952931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139169209 + 90000 = 11797^2 + 300^2 .

It is an emirp because it is prime and its reverse (902952931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139259209 - 2³ = 139259201 is a prime.

It is not a weakly prime, because it can be changed into another prime (139259201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69629604 + 69629605.

It is an arithmetic number, because the mean of its divisors is an integer number (69629605).

Almost surely, 2^139259209 is an apocalyptic number.

It is an amenable number.

139259209 is a deficient number, since it is larger than the sum of its proper divisors (1).

139259209 is an equidigital number, since it uses as much as digits as its factorization.

139259209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 139259209 is about 11800.8139126079. The cubic root of 139259209 is about 518.3319441334.

The spelling of 139259209 in words is "one hundred thirty-nine million, two hundred fifty-nine thousand, two hundred nine".