66386689 has 2 divisors, whose sum is σ = 66386690. Its totient is φ = 66386688.

The previous prime is 66386681. The next prime is 66386699. The reversal of 66386689 is 98668366.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41216400 + 25170289 = 6420^2 + 5017^2 .

It is a cyclic number.

It is not a de Polignac number, because 66386689 - 2³ = 66386681 is a prime.

It is not a weakly prime, because it can be changed into another prime (66386681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33193344 + 33193345.

It is an arithmetic number, because the mean of its divisors is an integer number (33193345).

Almost surely, 2^66386689 is an apocalyptic number.

It is an amenable number.

66386689 is a deficient number, since it is larger than the sum of its proper divisors (1).

66386689 is an equidigital number, since it uses as much as digits as its factorization.

66386689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 52.

The square root of 66386689 is about 8147.8027099335. The cubic root of 66386689 is about 404.9117096571.

The spelling of 66386689 in words is "sixty-six million, three hundred eighty-six thousand, six hundred eighty-nine".