12643605 has 24 divisors (see below), whose sum is σ = 23602488. Its totient is φ = 6224256.

The previous prime is 12643573. The next prime is 12643613. The reversal of 12643605 is 50634621.

12643605 is a `hidden beast` number, since 12 + 6 + 43 + 605 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2965284 + 9678321 = 1722^2 + 3111^2 .

It is not a de Polignac number, because 12643605 - 2⁵ = 12643573 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10222 + ... + 11391.

It is an arithmetic number, because the mean of its divisors is an integer number (983437).

Almost surely, 2^12643605 is an apocalyptic number.

12643605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12643605 is a deficient number, since it is larger than the sum of its proper divisors (10958883).

12643605 is a wasteful number, since it uses less digits than its factorization.

12643605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21637 (or 21634 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 12643605 is about 3555.7847235174. The cubic root of 12643605 is about 232.9648003216.

The spelling of 12643605 in words is "twelve million, six hundred forty-three thousand, six hundred five".