13668661 has 2 divisors, whose sum is σ = 13668662. Its totient is φ = 13668660.

The previous prime is 13668653. The next prime is 13668679. The reversal of 13668661 is 16686631.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10929636 + 2739025 = 3306^2 + 1655^2 .

It is a cyclic number.

It is not a de Polignac number, because 13668661 - 2³ = 13668653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13668661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13668631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6834330 + 6834331.

It is an arithmetic number, because the mean of its divisors is an integer number (6834331).

Almost surely, 2^13668661 is an apocalyptic number.

It is an amenable number.

13668661 is a deficient number, since it is larger than the sum of its proper divisors (1).

13668661 is an equidigital number, since it uses as much as digits as its factorization.

13668661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 13668661 is about 3697.1152267680. The cubic root of 13668661 is about 239.0976591261.

The spelling of 13668661 in words is "thirteen million, six hundred sixty-eight thousand, six hundred sixty-one".