12644245421 has 2 divisors, whose sum is σ = 12644245422. Its totient is φ = 12644245420.

The previous prime is 12644245399. The next prime is 12644245429. The reversal of 12644245421 is 12454244621.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12462373225 + 181872196 = 111635^2 + 13486^2 .

It is a cyclic number.

It is not a de Polignac number, because 12644245421 - 2²² = 12640051117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12644245429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6322122710 + 6322122711.

It is an arithmetic number, because the mean of its divisors is an integer number (6322122711).

Almost surely, 2^12644245421 is an apocalyptic number.

It is an amenable number.

12644245421 is a deficient number, since it is larger than the sum of its proper divisors (1).

12644245421 is an equidigital number, since it uses as much as digits as its factorization.

12644245421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61440, while the sum is 35.

The spelling of 12644245421 in words is "twelve billion, six hundred forty-four million, two hundred forty-five thousand, four hundred twenty-one".