665100000 has 216 divisors, whose sum is σ = 2367270360. Its totient is φ = 177120000.

The previous prime is 665099983. The next prime is 665100001. The reversal of 665100000 is 1566.

665100000 is a `hidden beast` number, since 665 + 1 + 0 + 0 + 0 + 0 + 0 = 666.

665100000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665100001) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 899631 + ... + 900369.

It is an arithmetic number, because the mean of its divisors is an integer number (10959585).

Almost surely, 2^665100000 is an apocalyptic number.

665100000 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 665100000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1183635180).

665100000 is an abundant number, since it is smaller than the sum of its proper divisors (1702170360).

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

665100000 is an equidigital number, since it uses as much as digits as its factorization.

665100000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 665100000 is about 25789.5327604049. The cubic root of 665100000 is about 872.8956232993.

Adding to 665100000 its reverse (1566), we get a palindrome (665101566).

The spelling of 665100000 in words is "six hundred sixty-five million, one hundred thousand".