13221321 has 16 divisors (see below), whose sum is σ = 19060800. Its totient is φ = 8123328.

The previous prime is 13221317. The next prime is 13221337. The reversal of 13221321 is 12312231.

It is not a de Polignac number, because 13221321 - 2² = 13221317 is a prime.

It is a super-3 number, since 3×13221321³ (a number of 22 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 13221321.

It is not an unprimeable number, because it can be changed into a prime (13221421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1026 + ... + 5243.

It is an arithmetic number, because the mean of its divisors is an integer number (1191300).

Almost surely, 2^13221321 is an apocalyptic number.

It is an amenable number.

13221321 is a deficient number, since it is larger than the sum of its proper divisors (5839479).

13221321 is a wasteful number, since it uses less digits than its factorization.

13221321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6328.

The product of its digits is 72, while the sum is 15.

The square root of 13221321 is about 3636.1134470750. The cubic root of 13221321 is about 236.4603255621.

Adding to 13221321 its reverse (12312231), we get a palindrome (25533552).

The spelling of 13221321 in words is "thirteen million, two hundred twenty-one thousand, three hundred twenty-one".