66427609 has 2 divisors, whose sum is σ = 66427610. Its totient is φ = 66427608.

The previous prime is 66427589. The next prime is 66427631. The reversal of 66427609 is 90672466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59521225 + 6906384 = 7715^2 + 2628^2 .

It is a cyclic number.

It is not a de Polignac number, because 66427609 - 2⁵ = 66427577 is a prime.

It is not a weakly prime, because it can be changed into another prime (66427649) 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, 33213804 + 33213805.

It is an arithmetic number, because the mean of its divisors is an integer number (33213805).

Almost surely, 2^66427609 is an apocalyptic number.

It is an amenable number.

66427609 is a deficient number, since it is larger than the sum of its proper divisors (1).

66427609 is an equidigital number, since it uses as much as digits as its factorization.

66427609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 40.

The square root of 66427609 is about 8150.3134295559. The cubic root of 66427609 is about 404.9948868937.

The spelling of 66427609 in words is "sixty-six million, four hundred twenty-seven thousand, six hundred nine".