12640705 has 16 divisors (see below), whose sum is σ = 18912384. Its totient is φ = 7879680.

The previous prime is 12640703. The next prime is 12640709. The reversal of 12640705 is 50704621.

It is not a de Polignac number, because 12640705 - 2¹ = 12640703 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12640705.

It is not an unprimeable number, because it can be changed into a prime (12640703) 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, 16032 + ... + 16801.

It is an arithmetic number, because the mean of its divisors is an integer number (1182024).

Almost surely, 2^12640705 is an apocalyptic number.

It is an amenable number.

12640705 is a deficient number, since it is larger than the sum of its proper divisors (6271679).

12640705 is a wasteful number, since it uses less digits than its factorization.

12640705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32856.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 12640705 is about 3555.3769139150. The cubic root of 12640705 is about 232.9469876386.

The spelling of 12640705 in words is "twelve million, six hundred forty thousand, seven hundred five".