669839 has 2 divisors, whose sum is σ = 669840.
Its totient is φ = 669838.
The previous prime is 669791. The next prime is 669847. The reversal of 669839 is 938966.
669839 is digitally balanced in base 2, 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 2k-669839 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 669796 and 669805.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (669859) by changing a digit.
It is a good prime.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334919 + 334920.
It is an arithmetic number, because the mean of its divisors is an integer number (334920).
2669839 is an apocalyptic number.
669839 is a deficient number, since it is larger than the sum of its proper divisors (1).
669839 is an equidigital number, since it uses as much as digits as its factorization.
669839 is an evil number, because the sum of its binary digits is even.
The product of its digits is 69984, while the sum is 41.
The square root of 669839 is about 818.4369248757.
The cubic root of 669839 is about 87.4963916879.
The spelling of 669839 in words is "six hundred sixty-nine thousand, eight hundred thirty-nine".