668044439 has 2 divisors, whose sum is σ = 668044440. Its totient is φ = 668044438.

The previous prime is 668044411. The next prime is 668044441. The reversal of 668044439 is 934440866.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668044439 is a prime.

It is a Sophie Germain prime.

Together with 668044441, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 668044439.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668044409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334022219 + 334022220.

It is an arithmetic number, because the mean of its divisors is an integer number (334022220).

Almost surely, 2^668044439 is an apocalyptic number.

668044439 is a deficient number, since it is larger than the sum of its proper divisors (1).

668044439 is an equidigital number, since it uses as much as digits as its factorization.

668044439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 497664, while the sum is 44.

The square root of 668044439 is about 25846.5556506085. Note that the first 3 decimals coincide. The cubic root of 668044439 is about 874.1818481393.

The spelling of 668044439 in words is "six hundred sixty-eight million, forty-four thousand, four hundred thirty-nine".