668798789 has 2 divisors, whose sum is σ = 668798790. Its totient is φ = 668798788.

The previous prime is 668798731. The next prime is 668798833. The reversal of 668798789 is 987897866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 527069764 + 141729025 = 22958^2 + 11905^2 .

It is a cyclic number.

It is not a de Polignac number, because 668798789 - 2²⁸ = 400363333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668798089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334399394 + 334399395.

It is an arithmetic number, because the mean of its divisors is an integer number (334399395).

Almost surely, 2^668798789 is an apocalyptic number.

It is an amenable number.

668798789 is a deficient number, since it is larger than the sum of its proper divisors (1).

668798789 is an equidigital number, since it uses as much as digits as its factorization.

668798789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73156608, while the sum is 68.

The square root of 668798789 is about 25861.1443868983. The cubic root of 668798789 is about 874.5107638936.

The spelling of 668798789 in words is "six hundred sixty-eight million, seven hundred ninety-eight thousand, seven hundred eighty-nine".