6643641416 has 8 divisors (see below), whose sum is σ = 12456827670. Its totient is φ = 3321820704.

The previous prime is 6643641391. The next prime is 6643641439. The reversal of 6643641416 is 6141463466.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 3617541316 + 3026100100 = 60146^2 + 55010^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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, 415227581 + ... + 415227596.

Almost surely, 2^6643641416 is an apocalyptic number.

It is an amenable number.

6643641416 is a deficient number, since it is larger than the sum of its proper divisors (5813186254).

6643641416 is a wasteful number, since it uses less digits than its factorization.

6643641416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830455183 (or 830455179 counting only the distinct ones).

The product of its digits is 248832, while the sum is 41.

The square root of 6643641416 is about 81508.5358474804. The cubic root of 6643641416 is about 1879.9027994110.

The spelling of 6643641416 in words is "six billion, six hundred forty-three million, six hundred forty-one thousand, four hundred sixteen".