6640421311 has 2 divisors, whose sum is σ = 6640421312. Its totient is φ = 6640421310.

The previous prime is 6640421299. The next prime is 6640421327. The reversal of 6640421311 is 1131240466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6640421311 - 2¹⁵ = 6640388543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6640421311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6640421911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3320210655 + 3320210656.

It is an arithmetic number, because the mean of its divisors is an integer number (3320210656).

Almost surely, 2^6640421311 is an apocalyptic number.

6640421311 is a deficient number, since it is larger than the sum of its proper divisors (1).

6640421311 is an equidigital number, since it uses as much as digits as its factorization.

6640421311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 6640421311 is about 81488.7802767964. The cubic root of 6640421311 is about 1879.5990271116.

Adding to 6640421311 its reverse (1131240466), we get a palindrome (7771661777).

The spelling of 6640421311 in words is "six billion, six hundred forty million, four hundred twenty-one thousand, three hundred eleven".