66916769 has 2 divisors, whose sum is σ = 66916770. Its totient is φ = 66916768.

The previous prime is 66916753. The next prime is 66916771. The reversal of 66916769 is 96761966.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45387169 + 21529600 = 6737^2 + 4640^2 .

It is a cyclic number.

It is not a de Polignac number, because 66916769 - 2⁴ = 66916753 is a prime.

It is a super-2 number, since 2×66916769² = 8955707946798722, which contains 22 as substring.

Together with 66916771, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66916789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33458384 + 33458385.

It is an arithmetic number, because the mean of its divisors is an integer number (33458385).

Almost surely, 2^66916769 is an apocalyptic number.

It is an amenable number.

66916769 is a deficient number, since it is larger than the sum of its proper divisors (1).

66916769 is an equidigital number, since it uses as much as digits as its factorization.

66916769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 50.

The square root of 66916769 is about 8180.2670494306. The cubic root of 66916769 is about 405.9865579119.

The spelling of 66916769 in words is "sixty-six million, nine hundred sixteen thousand, seven hundred sixty-nine".