667779899 has 2 divisors, whose sum is σ = 667779900. Its totient is φ = 667779898.

The previous prime is 667779887. The next prime is 667779929. The reversal of 667779899 is 998977766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 667779899 - 2⁴ = 667779883 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (667779829) 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, 333889949 + 333889950.

It is an arithmetic number, because the mean of its divisors is an integer number (333889950).

Almost surely, 2^667779899 is an apocalyptic number.

667779899 is a deficient number, since it is larger than the sum of its proper divisors (1).

667779899 is an equidigital number, since it uses as much as digits as its factorization.

667779899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72013536, while the sum is 68.

The square root of 667779899 is about 25841.4376341565. The cubic root of 667779899 is about 874.0664433426.

The spelling of 667779899 in words is "six hundred sixty-seven million, seven hundred seventy-nine thousand, eight hundred ninety-nine".