135611221 has 4 divisors (see below), whose sum is σ = 140287500. Its totient is φ = 130934944.

The previous prime is 135611219. The next prime is 135611233. The reversal of 135611221 is 122116531.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 63123025 + 72488196 = 7945^2 + 8514^2 .

It is a cyclic number.

It is not a de Polignac number, because 135611221 - 2¹ = 135611219 is a prime.

It is a super-2 number, since 2×135611221² = 36780806522221682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 135611192 and 135611201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135611291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2338096 + ... + 2338153.

It is an arithmetic number, because the mean of its divisors is an integer number (35071875).

Almost surely, 2^135611221 is an apocalyptic number.

It is an amenable number.

135611221 is a deficient number, since it is larger than the sum of its proper divisors (4676279).

135611221 is an equidigital number, since it uses as much as digits as its factorization.

135611221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4676278.

The product of its digits is 360, while the sum is 22.

The square root of 135611221 is about 11645.2230979059. The cubic root of 135611221 is about 513.7658208928.

Adding to 135611221 its reverse (122116531), we get a palindrome (257727752).

The spelling of 135611221 in words is "one hundred thirty-five million, six hundred eleven thousand, two hundred twenty-one".