13666686 has 32 divisors (see below), whose sum is σ = 30388608. Its totient is φ = 4062240.

The previous prime is 13666673. The next prime is 13666687. The reversal of 13666686 is 68666631.

13666686 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13666687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1545 + ... + 5451.

It is an arithmetic number, because the mean of its divisors is an integer number (949644).

Almost surely, 2^13666686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13666686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15194304).

13666686 is an abundant number, since it is smaller than the sum of its proper divisors (16721922).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13666686 is a wasteful number, since it uses less digits than its factorization.

13666686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3976.

The product of its digits is 186624, while the sum is 42.

The square root of 13666686 is about 3696.8481169775. The cubic root of 13666686 is about 239.0861427427.

Subtracting 13666686 from its reverse (68666631), we obtain a palindrome (54999945).

The spelling of 13666686 in words is "thirteen million, six hundred sixty-six thousand, six hundred eighty-six".