135545209 has 2 divisors, whose sum is σ = 135545210. Its totient is φ = 135545208.

The previous prime is 135545147. The next prime is 135545231. The reversal of 135545209 is 902545531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124255609 + 11289600 = 11147^2 + 3360^2 .

It is an emirp because it is prime and its reverse (902545531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 135545209 - 2²¹ = 133448057 is a prime.

It is not a weakly prime, because it can be changed into another prime (135545239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67772604 + 67772605.

It is an arithmetic number, because the mean of its divisors is an integer number (67772605).

Almost surely, 2^135545209 is an apocalyptic number.

It is an amenable number.

135545209 is a deficient number, since it is larger than the sum of its proper divisors (1).

135545209 is an equidigital number, since it uses as much as digits as its factorization.

135545209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 34.

The square root of 135545209 is about 11642.3884577006. The cubic root of 135545209 is about 513.6824447692.

It can be divided in two parts, 1355 and 45209, that added together give a palindrome (46564).

The spelling of 135545209 in words is "one hundred thirty-five million, five hundred forty-five thousand, two hundred nine".