139527209 has 2 divisors, whose sum is σ = 139527210. Its totient is φ = 139527208.

The previous prime is 139527197. The next prime is 139527221. The reversal of 139527209 is 902725931.

It is a balanced prime because it is at equal distance from previous prime (139527197) and next prime (139527221).

It can be written as a sum of positive squares in only one way, i.e., 81721600 + 57805609 = 9040^2 + 7603^2 .

It is an emirp because it is prime and its reverse (902725931) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139527209 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139527229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69763604 + 69763605.

It is an arithmetic number, because the mean of its divisors is an integer number (69763605).

Almost surely, 2^139527209 is an apocalyptic number.

It is an amenable number.

139527209 is a deficient number, since it is larger than the sum of its proper divisors (1).

139527209 is an equidigital number, since it uses as much as digits as its factorization.

139527209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 139527209 is about 11812.1636036757. The cubic root of 139527209 is about 518.6642356110.

The spelling of 139527209 in words is "one hundred thirty-nine million, five hundred twenty-seven thousand, two hundred nine".