666988424889666 has 24 divisors (see below), whose sum is σ = 1466272074552432. Its totient is φ = 202117704511800.

The previous prime is 666988424889649. The next prime is 666988424889667.

666988424889666 is nontrivially palindromic in base 10.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666988424889667) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 459358418620 + ... + 459358420071.

It is an arithmetic number, because the mean of its divisors is an integer number (61094669773018).

Almost surely, 2^{666988424889666} is an apocalyptic number.

666988424889666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666988424889666 is an abundant number, since it is smaller than the sum of its proper divisors (799283649662766).

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

666988424889666 is a wasteful number, since it uses less digits than its factorization.

666988424889666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918716838718 (or 918716838707 counting only the distinct ones).

The product of its digits is 495338913792, while the sum is 96.

The spelling of 666988424889666 in words is "six hundred sixty-six trillion, nine hundred eighty-eight billion, four hundred twenty-four million, eight hundred eighty-nine thousand, six hundred sixty-six".