66644453 has 16 divisors (see below), whose sum is σ = 70276800. Its totient is φ = 63141120.

The previous prime is 66644447. The next prime is 66644467. The reversal of 66644453 is 35444666.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66644453 - 2¹⁰ = 66643429 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66644423) 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 in 15 ways as a sum of consecutive naturals, for example, 276413 + ... + 276653.

It is an arithmetic number, because the mean of its divisors is an integer number (4392300).

Almost surely, 2^66644453 is an apocalyptic number.

It is an amenable number.

66644453 is a deficient number, since it is larger than the sum of its proper divisors (3632347).

66644453 is a wasteful number, since it uses less digits than its factorization.

66644453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452.

The product of its digits is 207360, while the sum is 38.

The square root of 66644453 is about 8163.6053922271. The cubic root of 66644453 is about 405.4350920327.

The spelling of 66644453 in words is "sixty-six million, six hundred forty-four thousand, four hundred fifty-three".