666334656 has 336 divisors, whose sum is σ = 2216725056. Its totient is φ = 189775872.

The previous prime is 666334649. The next prime is 666334657. The reversal of 666334656 is 656433666.

It is a happy number.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

Its product of digits (1399680) is a multiple of the sum of its prime factors (180).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666334657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9127836 + ... + 9127908.

It is an arithmetic number, because the mean of its divisors is an integer number (6597396).

Almost surely, 2^666334656 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 666334656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1108362528).

666334656 is an abundant number, since it is smaller than the sum of its proper divisors (1550390400).

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

666334656 is a wasteful number, since it uses less digits than its factorization.

666334656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 167 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 45.

The square root of 666334656 is about 25813.4588151220. The cubic root of 666334656 is about 873.4354216395.

It can be divided in two parts, 66633 and 4656, that added together give a square (71289 = 267²).

The spelling of 666334656 in words is "six hundred sixty-six million, three hundred thirty-four thousand, six hundred fifty-six".