6645380879 has 2 divisors, whose sum is σ = 6645380880. Its totient is φ = 6645380878.

The previous prime is 6645380849. The next prime is 6645380881. The reversal of 6645380879 is 9780835466.

6645380879 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6645380879 is a prime.

It is a super-2 number, since 2×6645380879² = 88322174053957625282, which contains 22 as substring.

Together with 6645380881, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6645380839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322690439 + 3322690440.

It is an arithmetic number, because the mean of its divisors is an integer number (3322690440).

Almost surely, 2^6645380879 is an apocalyptic number.

6645380879 is a deficient number, since it is larger than the sum of its proper divisors (1).

6645380879 is an equidigital number, since it uses as much as digits as its factorization.

6645380879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8709120, while the sum is 56.

The square root of 6645380879 is about 81519.2055837151. The cubic root of 6645380879 is about 1880.0668528173.

The spelling of 6645380879 in words is "six billion, six hundred forty-five million, three hundred eighty thousand, eight hundred seventy-nine".