666040064 has 36 divisors (see below), whose sum is σ = 1333145856. Its totient is φ = 332101632.

The previous prime is 666040033. The next prime is 666040087. The reversal of 666040064 is 460040666.

It is a happy number.

666040064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 666040064.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94652 + ... + 101444.

Almost surely, 2^666040064 is an apocalyptic number.

666040064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666040064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (666572928).

666040064 is an abundant number, since it is smaller than the sum of its proper divisors (667105792).

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

666040064 is an equidigital number, since it uses as much as digits as its factorization.

666040064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7192 (or 7178 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 666040064 is about 25807.7520136877. The cubic root of 666040064 is about 873.3066850184.

The spelling of 666040064 in words is "six hundred sixty-six million, forty thousand, sixty-four".