12643665 has 32 divisors (see below), whose sum is σ = 21617280. Its totient is φ = 6288384.

The previous prime is 12643661. The next prime is 12643669. The reversal of 12643665 is 56634621.

It is an interprime number because it is at equal distance from previous prime (12643661) and next prime (12643669).

It is not a de Polignac number, because 12643665 - 2² = 12643661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12643661) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 45507 + ... + 45783.

It is an arithmetic number, because the mean of its divisors is an integer number (675540).

Almost surely, 2^12643665 is an apocalyptic number.

12643665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12643665 is a deficient number, since it is larger than the sum of its proper divisors (8973615).

12643665 is a wasteful number, since it uses less digits than its factorization.

12643665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481.

The product of its digits is 25920, while the sum is 33.

The square root of 12643665 is about 3555.7931604636. The cubic root of 12643665 is about 232.9651688311.

The spelling of 12643665 in words is "twelve million, six hundred forty-three thousand, six hundred sixty-five".