666644787446666 has 32 divisors (see below), whose sum is σ = 1204314450340608. Its totient is φ = 270577184486400.

The previous prime is 666644787446663. The next prime is 666644787446719.

666644787446666 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (666644787446663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10249103255 + ... + 10249168298.

It is an arithmetic number, because the mean of its divisors is an integer number (37634826573144).

Almost surely, 2^{666644787446666} is an apocalyptic number.

666644787446666 is a deficient number, since it is larger than the sum of its proper divisors (537669662893942).

666644787446666 is a wasteful number, since it uses less digits than its factorization.

666644787446666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20498271686.

The product of its digits is 168552824832, while the sum is 86.

The spelling of 666644787446666 in words is "six hundred sixty-six trillion, six hundred forty-four billion, seven hundred eighty-seven million, four hundred forty-six thousand, six hundred sixty-six".