666423324666 has 128 divisors (see below), whose sum is σ = 1621343692800. Its totient is φ = 201226394880.

The previous prime is 666423324661. The next prime is 666423324709.

666423324666 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666423324661) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 255431170 + ... + 255433778.

It is an arithmetic number, because the mean of its divisors is an integer number (12666747600).

Almost surely, 2^666423324666 is an apocalyptic number.

666423324666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 666423324666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (810671846400).

666423324666 is an abundant number, since it is smaller than the sum of its proper divisors (954920368134).

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

666423324666 is a wasteful number, since it uses less digits than its factorization.

666423324666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4001 (or 3995 counting only the distinct ones).

The product of its digits is 26873856, while the sum is 54.

The spelling of 666423324666 in words is "six hundred sixty-six billion, four hundred twenty-three million, three hundred twenty-four thousand, six hundred sixty-six".