66544333221 has 8 divisors (see below), whose sum is σ = 90399849120. Its totient is φ = 43525853072.

The previous prime is 66544333181. The next prime is 66544333223. The reversal of 66544333221 is 12233344566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66544333221 - 2⁶ = 66544333157 is a prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66544333221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66544333223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 209258751 + ... + 209259068.

It is an arithmetic number, because the mean of its divisors is an integer number (11299981140).

Almost surely, 2^66544333221 is an apocalyptic number.

It is an amenable number.

66544333221 is a deficient number, since it is larger than the sum of its proper divisors (23855515899).

66544333221 is a wasteful number, since it uses less digits than its factorization.

66544333221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418517875.

The product of its digits is 311040, while the sum is 39.

Adding to 66544333221 its reverse (12233344566), we get a palindrome (78777677787).

The spelling of 66544333221 in words is "sixty-six billion, five hundred forty-four million, three hundred thirty-three thousand, two hundred twenty-one".