13633221 has 16 divisors (see below), whose sum is σ = 21200000. Its totient is φ = 7789824.

The previous prime is 13633199. The next prime is 13633223. The reversal of 13633221 is 12233631.

It is not a de Polignac number, because 13633221 - 2¹⁵ = 13600453 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13633223) 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, 5596 + ... + 7653.

It is an arithmetic number, because the mean of its divisors is an integer number (1325000).

Almost surely, 2^13633221 is an apocalyptic number.

It is an amenable number.

13633221 is a deficient number, since it is larger than the sum of its proper divisors (7566779).

13633221 is an equidigital number, since it uses as much as digits as its factorization.

13633221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13273 (or 13259 counting only the distinct ones).

The product of its digits is 648, while the sum is 21.

The square root of 13633221 is about 3692.3191898859. The cubic root of 13633221 is about 238.8908367447.

Adding to 13633221 its reverse (12233631), we get a palindrome (25866852).

The spelling of 13633221 in words is "thirteen million, six hundred thirty-three thousand, two hundred twenty-one".