6436623643 has 2 divisors, whose sum is σ = 6436623644. Its totient is φ = 6436623642.

The previous prime is 6436623619. The next prime is 6436623649. The reversal of 6436623643 is 3463266346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6436623643 - 2⁹ = 6436623131 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6436623643.

It is not a weakly prime, because it can be changed into another prime (6436623649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3218311821 + 3218311822.

It is an arithmetic number, because the mean of its divisors is an integer number (3218311822).

Almost surely, 2^6436623643 is an apocalyptic number.

6436623643 is a deficient number, since it is larger than the sum of its proper divisors (1).

6436623643 is an equidigital number, since it uses as much as digits as its factorization.

6436623643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 43.

The square root of 6436623643 is about 80228.5712386803. The cubic root of 6436623643 is about 1860.1702972568.

Adding to 6436623643 its reverse (3463266346), we get a palindrome (9899889989).

The spelling of 6436623643 in words is "six billion, four hundred thirty-six million, six hundred twenty-three thousand, six hundred forty-three".