135201221 has 8 divisors (see below), whose sum is σ = 143287704. Its totient is φ = 127129600.

The previous prime is 135201211. The next prime is 135201233. The reversal of 135201221 is 122102531.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5013121 + 130188100 = 2239^2 + 11410^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 135201221 - 2²² = 131006917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 135201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135201211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19061 + ... + 25173.

It is an arithmetic number, because the mean of its divisors is an integer number (17910963).

Almost surely, 2^135201221 is an apocalyptic number.

It is an amenable number.

135201221 is a deficient number, since it is larger than the sum of its proper divisors (8086483).

135201221 is a wasteful number, since it uses less digits than its factorization.

135201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7431.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 135201221 is about 11627.6059874765. The cubic root of 135201221 is about 513.2475338226.

Adding to 135201221 its reverse (122102531), we get a palindrome (257303752).

It can be divided in two parts, 13520 and 1221, that added together give a palindrome (14741).

The spelling of 135201221 in words is "one hundred thirty-five million, two hundred one thousand, two hundred twenty-one".