12643646 has 4 divisors (see below), whose sum is σ = 18965472. Its totient is φ = 6321822.

The previous prime is 12643643. The next prime is 12643661. The reversal of 12643646 is 64634621.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12643643) 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, 3160910 + ... + 3160913.

It is an arithmetic number, because the mean of its divisors is an integer number (4741368).

Almost surely, 2^12643646 is an apocalyptic number.

12643646 is a deficient number, since it is larger than the sum of its proper divisors (6321826).

12643646 is an equidigital number, since it uses as much as digits as its factorization.

12643646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6321825.

The product of its digits is 20736, while the sum is 32.

The square root of 12643646 is about 3555.7904887662. The cubic root of 12643646 is about 232.9650521365.

The spelling of 12643646 in words is "twelve million, six hundred forty-three thousand, six hundred forty-six".