6643221166 has 8 divisors (see below), whose sum is σ = 10234151640. Its totient is φ = 3231837288.

The previous prime is 6643221163. The next prime is 6643221191. The reversal of 6643221166 is 6611223466.

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

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643221163) 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 in 3 ways as a sum of consecutive naturals, for example, 44886556 + ... + 44886703.

It is an arithmetic number, because the mean of its divisors is an integer number (1279268955).

Almost surely, 2^6643221166 is an apocalyptic number.

6643221166 is a deficient number, since it is larger than the sum of its proper divisors (3590930474).

6643221166 is a wasteful number, since it uses less digits than its factorization.

6643221166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89773298.

The product of its digits is 62208, while the sum is 37.

The square root of 6643221166 is about 81505.9578558525. The cubic root of 6643221166 is about 1879.8631602151.

The spelling of 6643221166 in words is "six billion, six hundred forty-three million, two hundred twenty-one thousand, one hundred sixty-six".