666431812 has 6 divisors (see below), whose sum is σ = 1166255678. Its totient is φ = 333215904.

The previous prime is 666431809. The next prime is 666431813. The reversal of 666431812 is 218134666.

It is a happy number.

666431812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 653006916 + 13424896 = 25554^2 + 3664^2 .

It is not an unprimeable number, because it can be changed into a prime (666431813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83303973 + ... + 83303980.

Almost surely, 2^666431812 is an apocalyptic number.

It is an amenable number.

666431812 is a deficient number, since it is larger than the sum of its proper divisors (499823866).

666431812 is a wasteful number, since it uses less digits than its factorization.

666431812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166607957 (or 166607955 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 666431812 is about 25815.3406330422. The cubic root of 666431812 is about 873.4778704636.

The spelling of 666431812 in words is "six hundred sixty-six million, four hundred thirty-one thousand, eight hundred twelve".