666640012 has 6 divisors (see below), whose sum is σ = 1166620028. Its totient is φ = 333320004.

The previous prime is 666640001. The next prime is 666640019. The reversal of 666640012 is 210046666.

It is not an unprimeable number, because it can be changed into a prime (666640019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83329998 + ... + 83330005.

Almost surely, 2^666640012 is an apocalyptic number.

It is an amenable number.

666640012 is a deficient number, since it is larger than the sum of its proper divisors (499980016).

666640012 is a wasteful number, since it uses less digits than its factorization.

666640012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166660007 (or 166660005 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 666640012 is about 25819.3728041562. The cubic root of 666640012 is about 873.5688220831.

Adding to 666640012 its reverse (210046666), we get a palindrome (876686678).

The spelling of 666640012 in words is "six hundred sixty-six million, six hundred forty thousand, twelve".