13221421 has 2 divisors, whose sum is σ = 13221422. Its totient is φ = 13221420.

The previous prime is 13221413. The next prime is 13221431. The reversal of 13221421 is 12412231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13176900 + 44521 = 3630^2 + 211^2 .

It is a cyclic number.

It is not a de Polignac number, because 13221421 - 2³ = 13221413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13221395 and 13221404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13221401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6610710 + 6610711.

It is an arithmetic number, because the mean of its divisors is an integer number (6610711).

Almost surely, 2^13221421 is an apocalyptic number.

It is an amenable number.

13221421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13221421 is an equidigital number, since it uses as much as digits as its factorization.

13221421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 16.

The square root of 13221421 is about 3636.1271979951. The cubic root of 13221421 is about 236.4609217197.

Adding to 13221421 its reverse (12412231), we get a palindrome (25633652).

The spelling of 13221421 in words is "thirteen million, two hundred twenty-one thousand, four hundred twenty-one".