135786221 has 2 divisors, whose sum is σ = 135786222. Its totient is φ = 135786220.

The previous prime is 135786187. The next prime is 135786229. The reversal of 135786221 is 122687531.

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., 121308196 + 14478025 = 11014^2 + 3805^2 .

It is a cyclic number.

It is not a de Polignac number, because 135786221 - 2¹⁰ = 135785197 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 (135786229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67893110 + 67893111.

It is an arithmetic number, because the mean of its divisors is an integer number (67893111).

Almost surely, 2^135786221 is an apocalyptic number.

It is an amenable number.

135786221 is a deficient number, since it is larger than the sum of its proper divisors (1).

135786221 is an equidigital number, since it uses as much as digits as its factorization.

135786221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 35.

The square root of 135786221 is about 11652.7344859479. The cubic root of 135786221 is about 513.9867228979.

It can be divided in two parts, 1357 and 86221, that added together give a palindrome (87578).

The spelling of 135786221 in words is "one hundred thirty-five million, seven hundred eighty-six thousand, two hundred twenty-one".