136656209 has 2 divisors, whose sum is σ = 136656210. Its totient is φ = 136656208.

The previous prime is 136656203. The next prime is 136656229. The reversal of 136656209 is 902656631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97318225 + 39337984 = 9865^2 + 6272^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-136656209 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (136656203) 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 as a sum of consecutive naturals, namely, 68328104 + 68328105.

It is an arithmetic number, because the mean of its divisors is an integer number (68328105).

Almost surely, 2^136656209 is an apocalyptic number.

It is an amenable number.

136656209 is a deficient number, since it is larger than the sum of its proper divisors (1).

136656209 is an equidigital number, since it uses as much as digits as its factorization.

136656209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 136656209 is about 11690.0046621034. The cubic root of 136656209 is about 515.0820983265.

It can be divided in two parts, 1366 and 56209, that added together give a palindrome (57575).

The spelling of 136656209 in words is "one hundred thirty-six million, six hundred fifty-six thousand, two hundred nine".