13243666 has 4 divisors (see below), whose sum is σ = 19865502. Its totient is φ = 6621832.

The previous prime is 13243661. The next prime is 13243717. The reversal of 13243666 is 66634231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66634231 = 631 ⋅105601.

It can be written as a sum of positive squares in only one way, i.e., 13140625 + 103041 = 3625^2 + 321^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (13243661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3310915 + ... + 3310918.

Almost surely, 2^13243666 is an apocalyptic number.

13243666 is a deficient number, since it is larger than the sum of its proper divisors (6621836).

13243666 is an equidigital number, since it uses as much as digits as its factorization.

13243666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6621835.

The product of its digits is 15552, while the sum is 31.

The square root of 13243666 is about 3639.1847988251. The cubic root of 13243666 is about 236.5934623379.

Adding to 13243666 its reverse (66634231), we get a palindrome (79877897).

The spelling of 13243666 in words is "thirteen million, two hundred forty-three thousand, six hundred sixty-six".