135221420242261 has 2 divisors, whose sum is σ = 135221420242262. Its totient is φ = 135221420242260.

The previous prime is 135221420242231. The next prime is 135221420242289. The reversal of 135221420242261 is 162242024122531.

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., 122361981210225 + 12859439032036 = 11061735^2 + 3586006^2 .

It is a cyclic number.

It is not a de Polignac number, because 135221420242261 - 2⁹ = 135221420241749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 135221420242261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135221420242231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67610710121130 + 67610710121131.

It is an arithmetic number, because the mean of its divisors is an integer number (67610710121131).

Almost surely, 2^{135221420242261} is an apocalyptic number.

It is an amenable number.

135221420242261 is a deficient number, since it is larger than the sum of its proper divisors (1).

135221420242261 is an equidigital number, since it uses as much as digits as its factorization.

135221420242261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 92160, while the sum is 37.

Adding to 135221420242261 its reverse (162242024122531), we get a palindrome (297463444364792).

The spelling of 135221420242261 in words is "one hundred thirty-five trillion, two hundred twenty-one billion, four hundred twenty million, two hundred forty-two thousand, two hundred sixty-one".