13990666 has 4 divisors (see below), whose sum is σ = 20986002. Its totient is φ = 6995332.

The previous prime is 13990657. The next prime is 13990667. The reversal of 13990666 is 66609931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66609931 = 3709 ⋅17959.

It can be written as a sum of positive squares in only one way, i.e., 13535041 + 455625 = 3679^2 + 675^2 .

It is a Smith number, since the sum of its digits (40) 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 (13990667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3497665 + ... + 3497668.

Almost surely, 2^13990666 is an apocalyptic number.

13990666 is a deficient number, since it is larger than the sum of its proper divisors (6995336).

13990666 is an equidigital number, since it uses as much as digits as its factorization.

13990666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6995335.

The product of its (nonzero) digits is 52488, while the sum is 40.

The square root of 13990666 is about 3740.4098705891. The cubic root of 13990666 is about 240.9606519669.

The spelling of 13990666 in words is "thirteen million, nine hundred ninety thousand, six hundred sixty-six".