666326429 has 2 divisors, whose sum is σ = 666326430. Its totient is φ = 666326428.

The previous prime is 666326411. The next prime is 666326449. The reversal of 666326429 is 924623666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 433763929 + 232562500 = 20827^2 + 15250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666326429 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 666326429.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666326449) 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, 333163214 + 333163215.

It is an arithmetic number, because the mean of its divisors is an integer number (333163215).

Almost surely, 2^666326429 is an apocalyptic number.

It is an amenable number.

666326429 is a deficient number, since it is larger than the sum of its proper divisors (1).

666326429 is an equidigital number, since it uses as much as digits as its factorization.

666326429 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 44.

The square root of 666326429 is about 25813.2994597746. The cubic root of 666326429 is about 873.4318269579.

The spelling of 666326429 in words is "six hundred sixty-six million, three hundred twenty-six thousand, four hundred twenty-nine".