667688929 has 2 divisors, whose sum is σ = 667688930. Its totient is φ = 667688928.

The previous prime is 667688893. The next prime is 667688933. The reversal of 667688929 is 929886766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 379470400 + 288218529 = 19480^2 + 16977^2 .

It is a cyclic number.

It is not a de Polignac number, because 667688929 - 2¹¹ = 667686881 is a prime.

It is not a weakly prime, because it can be changed into another prime (667688129) 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, 333844464 + 333844465.

It is an arithmetic number, because the mean of its divisors is an integer number (333844465).

Almost surely, 2^667688929 is an apocalyptic number.

It is an amenable number.

667688929 is a deficient number, since it is larger than the sum of its proper divisors (1).

667688929 is an equidigital number, since it uses as much as digits as its factorization.

667688929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15676416, while the sum is 61.

The square root of 667688929 is about 25839.6774167171. The cubic root of 667688929 is about 874.0267509053.

The spelling of 667688929 in words is "six hundred sixty-seven million, six hundred eighty-eight thousand, nine hundred twenty-nine".