66665629 has 2 divisors, whose sum is σ = 66665630. Its totient is φ = 66665628.

The previous prime is 66665611. The next prime is 66665633. The reversal of 66665629 is 92656666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66504025 + 161604 = 8155^2 + 402^2 .

It is a cyclic number.

It is not a de Polignac number, because 66665629 - 2⁹ = 66665117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66665329) 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, 33332814 + 33332815.

It is an arithmetic number, because the mean of its divisors is an integer number (33332815).

Almost surely, 2^66665629 is an apocalyptic number.

It is an amenable number.

66665629 is a deficient number, since it is larger than the sum of its proper divisors (1).

66665629 is an equidigital number, since it uses as much as digits as its factorization.

66665629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 46.

The square root of 66665629 is about 8164.9022651836. The cubic root of 66665629 is about 405.4780292612.

The spelling of 66665629 in words is "sixty-six million, six hundred sixty-five thousand, six hundred twenty-nine".