13221231 has 8 divisors (see below), whose sum is σ = 17645184. Its totient is φ = 8805720.

The previous prime is 13221227. The next prime is 13221233. The reversal of 13221231 is 13212231.

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

It is not a de Polignac number, because 13221231 - 2² = 13221227 is a prime.

It is a super-2 number, since 2×13221231² = 349601898310722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 13221231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221233) 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, 4566 + ... + 6876.

It is an arithmetic number, because the mean of its divisors is an integer number (2205648).

Almost surely, 2^13221231 is an apocalyptic number.

13221231 is a deficient number, since it is larger than the sum of its proper divisors (4423953).

13221231 is a wasteful number, since it uses less digits than its factorization.

13221231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4221.

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

The square root of 13221231 is about 3636.1010712025. The cubic root of 13221231 is about 236.4597890177.

Adding to 13221231 its reverse (13212231), we get a palindrome (26433462).

The spelling of 13221231 in words is "thirteen million, two hundred twenty-one thousand, two hundred thirty-one".