12691663 has 4 divisors (see below), whose sum is σ = 12721408. Its totient is φ = 12661920.

The previous prime is 12691649. The next prime is 12691691. The reversal of 12691663 is 36619621.

12691663 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12691663 - 2⁵ = 12691631 is a prime.

It is a super-2 number, since 2×12691663² = 322156619411138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12692663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14223 + ... + 15088.

It is an arithmetic number, because the mean of its divisors is an integer number (3180352).

Almost surely, 2^12691663 is an apocalyptic number.

12691663 is a deficient number, since it is larger than the sum of its proper divisors (29745).

12691663 is an equidigital number, since it uses as much as digits as its factorization.

12691663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29744.

The product of its digits is 11664, while the sum is 34.

The square root of 12691663 is about 3562.5360349055. The cubic root of 12691663 is about 233.2595914365.

The spelling of 12691663 in words is "twelve million, six hundred ninety-one thousand, six hundred sixty-three".