66788069 has 2 divisors, whose sum is σ = 66788070. Its totient is φ = 66788068.

The previous prime is 66788063. The next prime is 66788077. The reversal of 66788069 is 96088766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35259844 + 31528225 = 5938^2 + 5615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66788069 is a prime.

It is a super-2 number, since 2×66788069² = 8921292321497522, which contains 22 as substring.

It is a Sophie Germain 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 (66788063) 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, 33394034 + 33394035.

It is an arithmetic number, because the mean of its divisors is an integer number (33394035).

Almost surely, 2^66788069 is an apocalyptic number.

It is an amenable number.

66788069 is a deficient number, since it is larger than the sum of its proper divisors (1).

66788069 is an equidigital number, since it uses as much as digits as its factorization.

66788069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 870912, while the sum is 50.

The square root of 66788069 is about 8172.3967720614. The cubic root of 66788069 is about 405.7261149561.

The spelling of 66788069 in words is "sixty-six million, seven hundred eighty-eight thousand, sixty-nine".