66694429 has 2 divisors, whose sum is σ = 66694430. Its totient is φ = 66694428.

The previous prime is 66694421. The next prime is 66694447. The reversal of 66694429 is 92449666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66096900 + 597529 = 8130^2 + 773^2 .

It is a cyclic number.

It is not a de Polignac number, because 66694429 - 2³ = 66694421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66694421) 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, 33347214 + 33347215.

It is an arithmetic number, because the mean of its divisors is an integer number (33347215).

Almost surely, 2^66694429 is an apocalyptic number.

It is an amenable number.

66694429 is a deficient number, since it is larger than the sum of its proper divisors (1).

66694429 is an equidigital number, since it uses as much as digits as its factorization.

66694429 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 46.

The square root of 66694429 is about 8166.6657210884. The cubic root of 66694429 is about 405.5364106000.

The spelling of 66694429 in words is "sixty-six million, six hundred ninety-four thousand, four hundred twenty-nine".