136542209 has 2 divisors, whose sum is σ = 136542210. Its totient is φ = 136542208.

The previous prime is 136542169. The next prime is 136542223. The reversal of 136542209 is 902245631.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94031809 + 42510400 = 9697^2 + 6520^2 .

It is a cyclic number.

It is not a de Polignac number, because 136542209 - 2¹² = 136538113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (136542239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68271104 + 68271105.

It is an arithmetic number, because the mean of its divisors is an integer number (68271105).

Almost surely, 2^136542209 is an apocalyptic number.

It is an amenable number.

136542209 is a deficient number, since it is larger than the sum of its proper divisors (1).

136542209 is an equidigital number, since it uses as much as digits as its factorization.

136542209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 136542209 is about 11685.1276843687. The cubic root of 136542209 is about 514.9388295713.

The spelling of 136542209 in words is "one hundred thirty-six million, five hundred forty-two thousand, two hundred nine".