13666729 has 2 divisors, whose sum is σ = 13666730. Its totient is φ = 13666728.

The previous prime is 13666721. The next prime is 13666769. The reversal of 13666729 is 92766631.

It is an a-pointer prime, because the next prime (13666769) can be obtained adding 13666729 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11042329 + 2624400 = 3323^2 + 1620^2 .

It is an emirp because it is prime and its reverse (92766631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13666729 - 2³ = 13666721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13666691 and 13666700.

It is not a weakly prime, because it can be changed into another prime (13666721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6833364 + 6833365.

It is an arithmetic number, because the mean of its divisors is an integer number (6833365).

Almost surely, 2^13666729 is an apocalyptic number.

It is an amenable number.

13666729 is a deficient number, since it is larger than the sum of its proper divisors (1).

13666729 is an equidigital number, since it uses as much as digits as its factorization.

13666729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 40.

The square root of 13666729 is about 3696.8539327379. The cubic root of 13666729 is about 239.0863934909.

The spelling of 13666729 in words is "thirteen million, six hundred sixty-six thousand, seven hundred twenty-nine".