13667221 has 4 divisors (see below), whose sum is σ = 14261472. Its totient is φ = 13072972.

The previous prime is 13667209. The next prime is 13667231. The reversal of 13667221 is 12276631.

13667221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13667221 - 2¹⁹ = 13142933 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13667221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13667231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 297091 + ... + 297136.

It is an arithmetic number, because the mean of its divisors is an integer number (3565368).

Almost surely, 2^13667221 is an apocalyptic number.

It is an amenable number.

13667221 is a deficient number, since it is larger than the sum of its proper divisors (594251).

13667221 is an equidigital number, since it uses as much as digits as its factorization.

13667221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594250.

The product of its digits is 3024, while the sum is 28.

The square root of 13667221 is about 3696.9204752064. The cubic root of 13667221 is about 239.0892624801.

The spelling of 13667221 in words is "thirteen million, six hundred sixty-seven thousand, two hundred twenty-one".