136206221 has 2 divisors, whose sum is σ = 136206222. Its totient is φ = 136206220.

The previous prime is 136206199. The next prime is 136206233. The reversal of 136206221 is 122602631.

136206221 is nontrivially palindromic in base 15.

136206221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89775625 + 46430596 = 9475^2 + 6814^2 .

It is an emirp because it is prime and its reverse (122602631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 136206221 - 2¹⁰ = 136205197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136206251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68103110 + 68103111.

It is an arithmetic number, because the mean of its divisors is an integer number (68103111).

Almost surely, 2^136206221 is an apocalyptic number.

It is an amenable number.

136206221 is a deficient number, since it is larger than the sum of its proper divisors (1).

136206221 is an equidigital number, since it uses as much as digits as its factorization.

136206221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 136206221 is about 11670.7420929434. The cubic root of 136206221 is about 514.5161144423.

Adding to 136206221 its reverse (122602631), we get a palindrome (258808852).

The spelling of 136206221 in words is "one hundred thirty-six million, two hundred six thousand, two hundred twenty-one".