13188221 has 2 divisors, whose sum is σ = 13188222. Its totient is φ = 13188220.

The previous prime is 13188199. The next prime is 13188239. The reversal of 13188221 is 12288131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 264196 = 3595^2 + 514^2 .

It is a cyclic number.

It is not a de Polignac number, because 13188221 - 2¹⁸ = 12926077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13188251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6594110 + 6594111.

It is an arithmetic number, because the mean of its divisors is an integer number (6594111).

Almost surely, 2^13188221 is an apocalyptic number.

It is an amenable number.

13188221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13188221 is an equidigital number, since it uses as much as digits as its factorization.

13188221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 768, while the sum is 26.

The square root of 13188221 is about 3631.5590316006. The cubic root of 13188221 is about 236.2628319971.

The spelling of 13188221 in words is "thirteen million, one hundred eighty-eight thousand, two hundred twenty-one".