13221649 has 4 divisors (see below), whose sum is σ = 15110464. Its totient is φ = 11332836.

The previous prime is 13221647. The next prime is 13221667. The reversal of 13221649 is 94612231.

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, and also an emirpimes, since its reverse is a distinct semiprime: 94612231 = 7 ⋅13516033.

It is a cyclic number.

It is not a de Polignac number, because 13221649 - 2¹ = 13221647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13221641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 944397 + ... + 944410.

It is an arithmetic number, because the mean of its divisors is an integer number (3777616).

Almost surely, 2^13221649 is an apocalyptic number.

It is an amenable number.

13221649 is a deficient number, since it is larger than the sum of its proper divisors (1888815).

13221649 is an equidigital number, since it uses as much as digits as its factorization.

13221649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888814.

The product of its digits is 2592, while the sum is 28.

The square root of 13221649 is about 3636.1585498985. The cubic root of 13221649 is about 236.4622809478.

The spelling of 13221649 in words is "thirteen million, two hundred twenty-one thousand, six hundred forty-nine".