13221261 has 12 divisors (see below), whose sum is σ = 19196892. Its totient is φ = 8768256.

The previous prime is 13221233. The next prime is 13221269. The reversal of 13221261 is 16212231.

13221261 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 9418761 + 3802500 = 3069^2 + 1950^2 .

It is not a de Polignac number, because 13221261 - 2⁹ = 13220749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221269) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1956 + ... + 5501.

It is an arithmetic number, because the mean of its divisors is an integer number (1599741).

Almost surely, 2^13221261 is an apocalyptic number.

It is an amenable number.

13221261 is a deficient number, since it is larger than the sum of its proper divisors (5975631).

13221261 is a wasteful number, since it uses less digits than its factorization.

13221261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7660 (or 7657 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 13221261 is about 3636.1051964980. The cubic root of 13221261 is about 236.4599678661.

Adding to 13221261 its reverse (16212231), we get a palindrome (29433492).

The spelling of 13221261 in words is "thirteen million, two hundred twenty-one thousand, two hundred sixty-one".