12400643 has 2 divisors, whose sum is σ = 12400644. Its totient is φ = 12400642.

The previous prime is 12400627. The next prime is 12400669. The reversal of 12400643 is 34600421.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (34600421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12400643 - 2⁴ = 12400627 is a prime.

It is not a weakly prime, because it can be changed into another prime (12400613) 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 as a sum of consecutive naturals, namely, 6200321 + 6200322.

It is an arithmetic number, because the mean of its divisors is an integer number (6200322).

Almost surely, 2^12400643 is an apocalyptic number.

12400643 is a deficient number, since it is larger than the sum of its proper divisors (1).

12400643 is an equidigital number, since it uses as much as digits as its factorization.

12400643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 12400643 is about 3521.4546710131. The cubic root of 12400643 is about 231.4629061382.

The spelling of 12400643 in words is "twelve million, four hundred thousand, six hundred forty-three".