666666672 has 120 divisors (see below), whose sum is σ = 1998372096. Its totient is φ = 187598592.

The previous prime is 666666667. The next prime is 666666691. The reversal of 666666672 is 276666666.

666666672 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (3919104) is a multiple of the sum of its prime divisors (288).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3991933 + ... + 3992099.

Almost surely, 2^666666672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666666672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (999186048).

666666672 is an abundant number, since it is smaller than the sum of its proper divisors (1331705424).

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

666666672 is a wasteful number, since it uses less digits than its factorization.

666666672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403 (or 288 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 51.

The square root of 666666672 is about 25819.8890779957. The cubic root of 666666672 is about 873.5804670658.

The spelling of 666666672 in words is "six hundred sixty-six million, six hundred sixty-six thousand, six hundred seventy-two".