13665121 has 2 divisors, whose sum is σ = 13665122. Its totient is φ = 13665120.

The previous prime is 13665107. The next prime is 13665133. The reversal of 13665121 is 12156631.

13665121 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8208225 + 5456896 = 2865^2 + 2336^2 .

It is an emirp because it is prime and its reverse (12156631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13665121 - 2¹⁷ = 13534049 is a prime.

It is not a weakly prime, because it can be changed into another prime (13665101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6832560 + 6832561.

It is an arithmetic number, because the mean of its divisors is an integer number (6832561).

Almost surely, 2^13665121 is an apocalyptic number.

It is an amenable number.

13665121 is a deficient number, since it is larger than the sum of its proper divisors (1).

13665121 is an equidigital number, since it uses as much as digits as its factorization.

13665121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 25.

The square root of 13665121 is about 3696.6364441205. The cubic root of 13665121 is about 239.0770163142.

The spelling of 13665121 in words is "thirteen million, six hundred sixty-five thousand, one hundred twenty-one".