13530221 has 4 divisors (see below), whose sum is σ = 13543452. Its totient is φ = 13516992.

The previous prime is 13530203. The next prime is 13530259. The reversal of 13530221 is 12203531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12203531 = 109 ⋅111959.

It can be written as a sum of positive squares in 2 ways, for example, as 2044900 + 11485321 = 1430^2 + 3389^2 .

It is a cyclic number.

It is not a de Polignac number, because 13530221 - 2²² = 9335917 is a prime.

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 13530221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13530421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4940 + ... + 7173.

It is an arithmetic number, because the mean of its divisors is an integer number (3385863).

Almost surely, 2^13530221 is an apocalyptic number.

It is an amenable number.

13530221 is a deficient number, since it is larger than the sum of its proper divisors (13231).

13530221 is a wasteful number, since it uses less digits than its factorization.

13530221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13230.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 13530221 is about 3678.3448723577. The cubic root of 13530221 is about 238.2877025894.

Adding to 13530221 its reverse (12203531), we get a palindrome (25733752).

The spelling of 13530221 in words is "thirteen million, five hundred thirty thousand, two hundred twenty-one".