666100800 has 336 divisors, whose sum is σ = 2573853120. Its totient is φ = 166993920.

The previous prime is 666100793. The next prime is 666100819. The reversal of 666100800 is 8001666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 733947 + ... + 734853.

Almost surely, 2^666100800 is an apocalyptic number.

666100800 is a gapful number since it is divisible by the number (60) 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 666100800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1286926560).

666100800 is an abundant number, since it is smaller than the sum of its proper divisors (1907752320).

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

666100800 is a wasteful number, since it uses less digits than its factorization.

666100800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 955 (or 934 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 666100800 is about 25808.9286875686. The cubic root of 666100800 is about 873.3332297393. Note that the first 3 decimals are identical.

The spelling of 666100800 in words is "six hundred sixty-six million, one hundred thousand, eight hundred".