66643470644 has 12 divisors (see below), whose sum is σ = 118102353600. Its totient is φ = 32899941048.

The previous prime is 66643470637. The next prime is 66643470679. The reversal of 66643470644 is 44607434666.

It is a junction number, because it is equal to n+sod(n) for n = 66643470592 and 66643470601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105448214 + ... + 105448845.

It is an arithmetic number, because the mean of its divisors is an integer number (9841862800).

Almost surely, 2^66643470644 is an apocalyptic number.

It is an amenable number.

66643470644 is a deficient number, since it is larger than the sum of its proper divisors (51458882956).

66643470644 is a wasteful number, since it uses less digits than its factorization.

66643470644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210897142 (or 210897140 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 50.

The spelling of 66643470644 in words is "sixty-six billion, six hundred forty-three million, four hundred seventy thousand, six hundred forty-four".