66044509 has 2 divisors, whose sum is σ = 66044510. Its totient is φ = 66044508.

The previous prime is 66044501. The next prime is 66044533. The reversal of 66044509 is 90544066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52925625 + 13118884 = 7275^2 + 3622^2 .

It is a cyclic number.

It is not a de Polignac number, because 66044509 - 2³ = 66044501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66044501) 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, 33022254 + 33022255.

It is an arithmetic number, because the mean of its divisors is an integer number (33022255).

Almost surely, 2^66044509 is an apocalyptic number.

It is an amenable number.

66044509 is a deficient number, since it is larger than the sum of its proper divisors (1).

66044509 is an equidigital number, since it uses as much as digits as its factorization.

66044509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 66044509 is about 8126.7772825395. Note that the first 3 decimals coincide. The cubic root of 66044509 is about 404.2148258669.

The spelling of 66044509 in words is "sixty-six million, forty-four thousand, five hundred nine".