66633689 has 2 divisors, whose sum is σ = 66633690. Its totient is φ = 66633688.

The previous prime is 66633661. The next prime is 66633701. The reversal of 66633689 is 98633666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60217600 + 6416089 = 7760^2 + 2533^2 .

It is a cyclic number.

It is not a de Polignac number, because 66633689 - 2⁸ = 66633433 is a prime.

It is not a weakly prime, because it can be changed into another prime (66633629) 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, 33316844 + 33316845.

It is an arithmetic number, because the mean of its divisors is an integer number (33316845).

Almost surely, 2^66633689 is an apocalyptic number.

It is an amenable number.

66633689 is a deficient number, since it is larger than the sum of its proper divisors (1).

66633689 is an equidigital number, since it uses as much as digits as its factorization.

66633689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 47.

The square root of 66633689 is about 8162.9460980702. The cubic root of 66633689 is about 405.4132630676.

The spelling of 66633689 in words is "sixty-six million, six hundred thirty-three thousand, six hundred eighty-nine".