6440779 has 2 divisors, whose sum is σ = 6440780. Its totient is φ = 6440778.

The previous prime is 6440771. The next prime is 6440783. The reversal of 6440779 is 9770446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6440779 - 2³ = 6440771 is a prime.

6440779 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6440771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220389 + 3220390.

It is an arithmetic number, because the mean of its divisors is an integer number (3220390).

Almost surely, 2^6440779 is an apocalyptic number.

6440779 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440779 is an equidigital number, since it uses as much as digits as its factorization.

6440779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 6440779 is about 2537.8689879503. The cubic root of 6440779 is about 186.0570507539.

The spelling of 6440779 in words is "six million, four hundred forty thousand, seven hundred seventy-nine".