136666217 has 2 divisors, whose sum is σ = 136666218. Its totient is φ = 136666216.

The previous prime is 136666199. The next prime is 136666249. The reversal of 136666217 is 712666631.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132273001 + 4393216 = 11501^2 + 2096^2 .

It is a cyclic number.

It is not a de Polignac number, because 136666217 - 2⁸ = 136665961 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (136266217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68333108 + 68333109.

It is an arithmetic number, because the mean of its divisors is an integer number (68333109).

Almost surely, 2^136666217 is an apocalyptic number.

It is an amenable number.

136666217 is a deficient number, since it is larger than the sum of its proper divisors (1).

136666217 is an equidigital number, since it uses as much as digits as its factorization.

136666217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 38.

The square root of 136666217 is about 11690.4327122652. The cubic root of 136666217 is about 515.0946720101.

The spelling of 136666217 in words is "one hundred thirty-six million, six hundred sixty-six thousand, two hundred seventeen".