666812928 has 80 divisors (see below), whose sum is σ = 1810169856. Its totient is φ = 218050560.

The previous prime is 666812917. The next prime is 666812957. The reversal of 666812928 is 829218666.

It is a happy number.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77313 + ... + 85503.

Almost surely, 2^666812928 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 666812928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (905084928).

666812928 is an abundant number, since it is smaller than the sum of its proper divisors (1143356928).

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

666812928 is an equidigital number, since it uses as much as digits as its factorization.

666812928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8265 (or 8249 counting only the distinct ones).

The product of its digits is 497664, while the sum is 48.

The square root of 666812928 is about 25822.7211579260. The cubic root of 666812928 is about 873.6443455867.

The spelling of 666812928 in words is "six hundred sixty-six million, eight hundred twelve thousand, nine hundred twenty-eight".