66887729 has 2 divisors, whose sum is σ = 66887730. Its totient is φ = 66887728.

The previous prime is 66887719. The next prime is 66887761. The reversal of 66887729 is 92778866.

It is a happy number.

66887729 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45589504 + 21298225 = 6752^2 + 4615^2 .

It is a cyclic number.

It is not a de Polignac number, because 66887729 - 2⁴ = 66887713 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (66887719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33443864 + 33443865.

It is an arithmetic number, because the mean of its divisors is an integer number (33443865).

Almost surely, 2^66887729 is an apocalyptic number.

It is an amenable number.

66887729 is a deficient number, since it is larger than the sum of its proper divisors (1).

66887729 is an equidigital number, since it uses as much as digits as its factorization.

66887729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2032128, while the sum is 53.

The square root of 66887729 is about 8178.4918536366. The cubic root of 66887729 is about 405.9278204897.

The spelling of 66887729 in words is "sixty-six million, eight hundred eighty-seven thousand, seven hundred twenty-nine".