666044020 has 48 divisors (see below), whose sum is σ = 1484517888. Its totient is φ = 250145280.

The previous prime is 666044009. The next prime is 666044033. The reversal of 666044020 is 20440666.

666044020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×666044020² = 887229273155520800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 666044020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155305 + ... + 159535.

It is an arithmetic number, because the mean of its divisors is an integer number (30927456).

Almost surely, 2^666044020 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 666044020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (742258944).

666044020 is an abundant number, since it is smaller than the sum of its proper divisors (818473868).

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

666044020 is a wasteful number, since it uses less digits than its factorization.

666044020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4720 (or 4718 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 666044020 is about 25807.8286572117. The cubic root of 666044020 is about 873.3084140408.

Adding to 666044020 its reverse (20440666), we get a palindrome (686484686).

The spelling of 666044020 in words is "six hundred sixty-six million, forty-four thousand, twenty".