666280000 has 70 divisors (see below), whose sum is σ = 1652257046. Its totient is φ = 266496000.

The previous prime is 666279989. The next prime is 666280001. The reversal of 666280000 is 82666.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 63872064 + 602407936 = 7992^2 + 24544^2 .

It is not an unprimeable number, because it can be changed into a prime (666280001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 31672 + ... + 48328.

Almost surely, 2^666280000 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 666280000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (826128523).

666280000 is an abundant number, since it is smaller than the sum of its proper divisors (985977046).

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

666280000 is an equidigital number, since it uses as much as digits as its factorization.

666280000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16689 (or 16664 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 666280000 is about 25812.4001208721. The cubic root of 666280000 is about 873.4115398501.

The spelling of 666280000 in words is "six hundred sixty-six million, two hundred eighty thousand".