135120209 has 4 divisors (see below), whose sum is σ = 154423104. Its totient is φ = 115817316.

The previous prime is 135120187. The next prime is 135120211. The reversal of 135120209 is 902021531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 902021531 = 613 ⋅1471487.

It is a cyclic number.

It is not a de Polignac number, because 135120209 - 2⁸ = 135119953 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135120259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9651437 + ... + 9651450.

It is an arithmetic number, because the mean of its divisors is an integer number (38605776).

Almost surely, 2^135120209 is an apocalyptic number.

It is an amenable number.

135120209 is a deficient number, since it is larger than the sum of its proper divisors (19302895).

135120209 is an equidigital number, since it uses as much as digits as its factorization.

135120209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19302894.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 135120209 is about 11624.1218593062. The cubic root of 135120209 is about 513.1450014235.

The spelling of 135120209 in words is "one hundred thirty-five million, one hundred twenty thousand, two hundred nine".