6643404263 has 2 divisors, whose sum is σ = 6643404264. Its totient is φ = 6643404262.

The previous prime is 6643404241. The next prime is 6643404281. The reversal of 6643404263 is 3624043466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6643404263 - 2²⁶ = 6576295399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6643404233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3321702131 + 3321702132.

It is an arithmetic number, because the mean of its divisors is an integer number (3321702132).

Almost surely, 2^6643404263 is an apocalyptic number.

6643404263 is a deficient number, since it is larger than the sum of its proper divisors (1).

6643404263 is an equidigital number, since it uses as much as digits as its factorization.

6643404263 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 248832, while the sum is 38.

The square root of 6643404263 is about 81507.0810604821. The cubic root of 6643404263 is about 1879.8804306594.

The spelling of 6643404263 in words is "six billion, six hundred forty-three million, four hundred four thousand, two hundred sixty-three".