13221457 has 2 divisors, whose sum is σ = 13221458. Its totient is φ = 13221456.

The previous prime is 13221443. The next prime is 13221479. The reversal of 13221457 is 75412231.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13220496 + 961 = 3636^2 + 31^2 .

It is an emirp because it is prime and its reverse (75412231) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13221457 is a prime.

It is not a weakly prime, because it can be changed into another prime (13221497) 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 as a sum of consecutive naturals, namely, 6610728 + 6610729.

It is an arithmetic number, because the mean of its divisors is an integer number (6610729).

Almost surely, 2^13221457 is an apocalyptic number.

It is an amenable number.

13221457 is a deficient number, since it is larger than the sum of its proper divisors (1).

13221457 is an equidigital number, since it uses as much as digits as its factorization.

13221457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 25.

The square root of 13221457 is about 3636.1321483136. The cubic root of 13221457 is about 236.4611363357.

Adding to 13221457 its reverse (75412231), we get a palindrome (88633688).

The spelling of 13221457 in words is "thirteen million, two hundred twenty-one thousand, four hundred fifty-seven".