66649459 has 2 divisors, whose sum is σ = 66649460. Its totient is φ = 66649458.

The previous prime is 66649439. The next prime is 66649481. The reversal of 66649459 is 95494666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66649459 - 2⁹ = 66648947 is a prime.

It is not a weakly prime, because it can be changed into another prime (66649439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33324729 + 33324730.

It is an arithmetic number, because the mean of its divisors is an integer number (33324730).

Almost surely, 2^66649459 is an apocalyptic number.

66649459 is a deficient number, since it is larger than the sum of its proper divisors (1).

66649459 is an equidigital number, since it uses as much as digits as its factorization.

66649459 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 49.

The square root of 66649459 is about 8163.9119911964. The cubic root of 66649459 is about 405.4452432013.

The spelling of 66649459 in words is "sixty-six million, six hundred forty-nine thousand, four hundred fifty-nine".