13221331 has 4 divisors (see below), whose sum is σ = 13268664.
Its totient is φ = 13174000.
The previous prime is 13221317. The next prime is 13221337. The reversal of 13221331 is 13312231.
Adding to 13221331 its reverse (13312231), we get a palindrome (26533562).
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is not a de Polignac number, because 13221331 - 213 = 13213139 is a prime.
It is a super-2 number, since 2×132213312 = 349607186823122, which contains 22 as substring.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (13221337) 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, 23245 + ... + 23806.
It is an arithmetic number, because the mean of its divisors is an integer number (3317166).
Almost surely, 213221331 is an apocalyptic number.
13221331 is a deficient number, since it is larger than the sum of its proper divisors (47333).
13221331 is an equidigital number, since it uses as much as digits as its factorization.
13221331 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 47332.
The product of its digits is 108, while the sum is 16.
The square root of 13221331 is about 3636.1148221694.
The cubic root of 13221331 is about 236.4603851780.
The spelling of 13221331 in words is "thirteen million, two hundred twenty-one thousand, three hundred thirty-one".