640660223543 has 2 divisors, whose sum is σ = 640660223544. Its totient is φ = 640660223542.

The previous prime is 640660223537. The next prime is 640660223561. The reversal of 640660223543 is 345322066046.

640660223543 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640660223543 - 2⁶ = 640660223479 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640660223543.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640660223443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320330111771 + 320330111772.

It is an arithmetic number, because the mean of its divisors is an integer number (320330111772).

Almost surely, 2^640660223543 is an apocalyptic number.

640660223543 is a deficient number, since it is larger than the sum of its proper divisors (1).

640660223543 is an equidigital number, since it uses as much as digits as its factorization.

640660223543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 41.

Adding to 640660223543 its reverse (345322066046), we get a palindrome (985982289589).

The spelling of 640660223543 in words is "six hundred forty billion, six hundred sixty million, two hundred twenty-three thousand, five hundred forty-three".