66643201 has 2 divisors, whose sum is σ = 66643202. Its totient is φ = 66643200.

The previous prime is 66643193. The next prime is 66643229. The reversal of 66643201 is 10234666.

66643201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (66643229) can be obtained adding 66643201 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55487601 + 11155600 = 7449^2 + 3340^2 .

It is a cyclic number.

It is not a de Polignac number, because 66643201 - 2³ = 66643193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66643201.

It is not a weakly prime, because it can be changed into another prime (66643271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33321600 + 33321601.

It is an arithmetic number, because the mean of its divisors is an integer number (33321601).

Almost surely, 2^66643201 is an apocalyptic number.

It is an amenable number.

66643201 is a deficient number, since it is larger than the sum of its proper divisors (1).

66643201 is an equidigital number, since it uses as much as digits as its factorization.

66643201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 66643201 is about 8163.5287100616. The cubic root of 66643201 is about 405.4325531471.

Adding to 66643201 its reverse (10234666), we get a palindrome (76877867).

The spelling of 66643201 in words is "sixty-six million, six hundred forty-three thousand, two hundred one".