66845689 has 2 divisors, whose sum is σ = 66845690. Its totient is φ = 66845688.

The previous prime is 66845687. The next prime is 66845711. The reversal of 66845689 is 98654866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41925625 + 24920064 = 6475^2 + 4992^2 .

It is a cyclic number.

It is not a de Polignac number, because 66845689 - 2¹ = 66845687 is a prime.

It is a super-2 number, since 2×66845689² = 8936692275769442, which contains 22 as substring.

Together with 66845687, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66845687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33422844 + 33422845.

It is an arithmetic number, because the mean of its divisors is an integer number (33422845).

Almost surely, 2^66845689 is an apocalyptic number.

It is an amenable number.

66845689 is a deficient number, since it is larger than the sum of its proper divisors (1).

66845689 is an equidigital number, since it uses as much as digits as its factorization.

66845689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2488320, while the sum is 52.

The square root of 66845689 is about 8175.9212936525. The cubic root of 66845689 is about 405.8427586389.

The spelling of 66845689 in words is "sixty-six million, eight hundred forty-five thousand, six hundred eighty-nine".