135817209 has 32 divisors (see below), whose sum is σ = 220164480. Its totient is φ = 82065600.

The previous prime is 135817193. The next prime is 135817243. The reversal of 135817209 is 902718531.

135817209 is a `hidden beast` number, since 1 + 3 + 581 + 72 + 0 + 9 = 666.

135817209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 135817209 - 2⁴ = 135817193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (135817289) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 165019 + ... + 165839.

It is an arithmetic number, because the mean of its divisors is an integer number (6880140).

Almost surely, 2^135817209 is an apocalyptic number.

It is an amenable number.

135817209 is a deficient number, since it is larger than the sum of its proper divisors (84347271).

135817209 is a wasteful number, since it uses less digits than its factorization.

135817209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398 (or 1392 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 135817209 is about 11654.0640550840. The cubic root of 135817209 is about 514.0258191797.

The spelling of 135817209 in words is "one hundred thirty-five million, eight hundred seventeen thousand, two hundred nine".