6721643611 has 2 divisors, whose sum is σ = 6721643612. Its totient is φ = 6721643610.

The previous prime is 6721643609. The next prime is 6721643629. The reversal of 6721643611 is 1163461276.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6721643611 - 2¹ = 6721643609 is a prime.

Together with 6721643609, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6721643011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3360821805 + 3360821806.

It is an arithmetic number, because the mean of its divisors is an integer number (3360821806).

Almost surely, 2^6721643611 is an apocalyptic number.

6721643611 is a deficient number, since it is larger than the sum of its proper divisors (1).

6721643611 is an equidigital number, since it uses as much as digits as its factorization.

6721643611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 37.

The square root of 6721643611 is about 81985.6305153531. The cubic root of 6721643611 is about 1887.2314298574.

The spelling of 6721643611 in words is "six billion, seven hundred twenty-one million, six hundred forty-three thousand, six hundred eleven".