135221 has 2 divisors, whose sum is σ = 135222. Its totient is φ = 135220.

The previous prime is 135211. The next prime is 135241. The reversal of 135221 is 122531.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130321 + 4900 = 361^2 + 70^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135221 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 135196 and 135205.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 135221.

It is not a weakly prime, because it can be changed into another prime (135211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67610 + 67611.

It is an arithmetic number, because the mean of its divisors is an integer number (67611).

2¹³⁵²²¹ is an apocalyptic number.

It is an amenable number.

135221 is a deficient number, since it is larger than the sum of its proper divisors (1).

135221 is an equidigital number, since it uses as much as digits as its factorization.

135221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60, while the sum is 14.

The square root of 135221 is about 367.7240813436. The cubic root of 135221 is about 51.3272560786.

Adding to 135221 its reverse (122531), we get a palindrome (257752).

The spelling of 135221 in words is "one hundred thirty-five thousand, two hundred twenty-one".