668186839 has 2 divisors, whose sum is σ = 668186840. Its totient is φ = 668186838.

The previous prime is 668186837. The next prime is 668186843. The reversal of 668186839 is 938681866.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668186839 - 2¹ = 668186837 is a prime.

Together with 668186837, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 668186839.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668186833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334093419 + 334093420.

It is an arithmetic number, because the mean of its divisors is an integer number (334093420).

Almost surely, 2^668186839 is an apocalyptic number.

668186839 is a deficient number, since it is larger than the sum of its proper divisors (1).

668186839 is an equidigital number, since it uses as much as digits as its factorization.

668186839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2985984, while the sum is 55.

The square root of 668186839 is about 25849.3102229054. The cubic root of 668186839 is about 874.2439571069.

The spelling of 668186839 in words is "six hundred sixty-eight million, one hundred eighty-six thousand, eight hundred thirty-nine".