135686909 has 4 divisors (see below), whose sum is σ = 135718080. Its totient is φ = 135655740.

The previous prime is 135686891. The next prime is 135686921. The reversal of 135686909 is 909686531.

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: 909686531 = 13 ⋅69975887.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135686909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135686009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7739 + ... + 18200.

It is an arithmetic number, because the mean of its divisors is an integer number (33929520).

Almost surely, 2^135686909 is an apocalyptic number.

It is an amenable number.

135686909 is a deficient number, since it is larger than the sum of its proper divisors (31171).

135686909 is an equidigital number, since it uses as much as digits as its factorization.

135686909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31170.

The product of its (nonzero) digits is 349920, while the sum is 47.

The square root of 135686909 is about 11648.4723891161. The cubic root of 135686909 is about 513.8613849496.

The spelling of 135686909 in words is "one hundred thirty-five million, six hundred eighty-six thousand, nine hundred nine".