13550221 has 8 divisors (see below), whose sum is σ = 14164920. Its totient is φ = 12945408.

The previous prime is 13550219. The next prime is 13550231. The reversal of 13550221 is 12205531.

13550221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 264196 + 13286025 = 514^2 + 3645^2 .

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 13550221 - 2¹ = 13550219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13550231) 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, 405 + ... + 5221.

It is an arithmetic number, because the mean of its divisors is an integer number (1770615).

Almost surely, 2^13550221 is an apocalyptic number.

It is an amenable number.

13550221 is a deficient number, since it is larger than the sum of its proper divisors (614699).

13550221 is an equidigital number, since it uses as much as digits as its factorization.

13550221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4943.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 13550221 is about 3681.0624824906. The cubic root of 13550221 is about 238.4050548922.

Adding to 13550221 its reverse (12205531), we get a palindrome (25755752).

The spelling of 13550221 in words is "thirteen million, five hundred fifty thousand, two hundred twenty-one".