664394429 has 2 divisors, whose sum is σ = 664394430. Its totient is φ = 664394428.

The previous prime is 664394417. The next prime is 664394443. The reversal of 664394429 is 924493466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 553660900 + 110733529 = 23530^2 + 10523^2 .

It is a cyclic number.

It is not a de Polignac number, because 664394429 - 2²⁴ = 647617213 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664394329) 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, 332197214 + 332197215.

It is an arithmetic number, because the mean of its divisors is an integer number (332197215).

Almost surely, 2^664394429 is an apocalyptic number.

It is an amenable number.

664394429 is a deficient number, since it is larger than the sum of its proper divisors (1).

664394429 is an equidigital number, since it uses as much as digits as its factorization.

664394429 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1119744, while the sum is 47.

The square root of 664394429 is about 25775.8497241119. The cubic root of 664394429 is about 872.5868437899.

The spelling of 664394429 in words is "six hundred sixty-four million, three hundred ninety-four thousand, four hundred twenty-nine".