13220645 has 8 divisors (see below), whose sum is σ = 16798104. Its totient is φ = 9954304.

The previous prime is 13220639. The next prime is 13220659. The reversal of 13220645 is 54602231.

It can be written as a sum of positive squares in 4 ways, for example, as 3678724 + 9541921 = 1918^2 + 3089^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13220645 - 2⁴ = 13220629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 13220645.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 77684 + ... + 77853.

It is an arithmetic number, because the mean of its divisors is an integer number (2099763).

Almost surely, 2^13220645 is an apocalyptic number.

It is an amenable number.

13220645 is a deficient number, since it is larger than the sum of its proper divisors (3577459).

13220645 is a wasteful number, since it uses less digits than its factorization.

13220645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155559.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 13220645 is about 3636.0204894912. The cubic root of 13220645 is about 236.4562954579.

Adding to 13220645 its reverse (54602231), we get a palindrome (67822876).

The spelling of 13220645 in words is "thirteen million, two hundred twenty thousand, six hundred forty-five".