666700406676 has 18 divisors (see below), whose sum is σ = 1685270472522. Its totient is φ = 222233468880.

The previous prime is 666700406657. The next prime is 666700406681. The reversal of 666700406676 is 676604007666.

It can be written as a sum of positive squares in only one way, i.e., 656381910276 + 10318496400 = 810174^2 + 101580^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9259727835 + ... + 9259727906.

Almost surely, 2^666700406676 is an apocalyptic number.

It is an amenable number.

666700406676 is an abundant number, since it is smaller than the sum of its proper divisors (1018570065846).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666700406676 is a wasteful number, since it uses less digits than its factorization.

666700406676 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18519455751 (or 18519455746 counting only the distinct ones).

The product of its (nonzero) digits is 9144576, while the sum is 54.

The spelling of 666700406676 in words is "six hundred sixty-six billion, seven hundred million, four hundred six thousand, six hundred seventy-six".