66798569 has 2 divisors, whose sum is σ = 66798570. Its totient is φ = 66798568.

The previous prime is 66798533. The next prime is 66798607. The reversal of 66798569 is 96589766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50694400 + 16104169 = 7120^2 + 4013^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66798569 is a prime.

It is a super-2 number, since 2×66798569² = 8924097640895522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66798469) 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, 33399284 + 33399285.

It is an arithmetic number, because the mean of its divisors is an integer number (33399285).

Almost surely, 2^66798569 is an apocalyptic number.

It is an amenable number.

66798569 is a deficient number, since it is larger than the sum of its proper divisors (1).

66798569 is an equidigital number, since it uses as much as digits as its factorization.

66798569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4898880, while the sum is 56.

The square root of 66798569 is about 8173.0391532159. The cubic root of 66798569 is about 405.7473757443.

The spelling of 66798569 in words is "sixty-six million, seven hundred ninety-eight thousand, five hundred sixty-nine".