135212221 has 2 divisors, whose sum is σ = 135212222. Its totient is φ = 135212220.

The previous prime is 135212191. The next prime is 135212257. The reversal of 135212221 is 122212531.

135212221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134815321 + 396900 = 11611^2 + 630^2 .

It is a cyclic number.

It is not a de Polignac number, because 135212221 - 2¹³ = 135204029 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135212281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67606110 + 67606111.

It is an arithmetic number, because the mean of its divisors is an integer number (67606111).

Almost surely, 2^135212221 is an apocalyptic number.

It is an amenable number.

135212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

135212221 is an equidigital number, since it uses as much as digits as its factorization.

135212221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 19.

The square root of 135212221 is about 11628.0789900998. The cubic root of 135212221 is about 513.2614527545.

Adding to 135212221 its reverse (122212531), we get a palindrome (257424752).

The spelling of 135212221 in words is "one hundred thirty-five million, two hundred twelve thousand, two hundred twenty-one".