66844644866 has 16 divisors (see below), whose sum is σ = 103773088440. Its totient is φ = 32254696320.

The previous prime is 66844644809. The next prime is 66844644883.

66844644866 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 53933095225 + 12911549641 = 232235^2 + 113629^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66844644799 and 66844644808.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144971 + ... + 393326.

Almost surely, 2^66844644866 is an apocalyptic number.

66844644866 is a deficient number, since it is larger than the sum of its proper divisors (36928443574).

66844644866 is a wasteful number, since it uses less digits than its factorization.

66844644866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540469.

The product of its digits is 127401984, while the sum is 62.

The spelling of 66844644866 in words is "sixty-six billion, eight hundred forty-four million, six hundred forty-four thousand, eight hundred sixty-six".