665109216000 has 1728 divisors, whose sum is σ = 2674172067840. Its totient is φ = 158146560000.

The previous prime is 665109215983. The next prime is 665109216001. The reversal of 665109216000 is 612901566.

665109216000 is a `hidden beast` number, since 66 + 510 + 9 + 21 + 60 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (665109216001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 8419103961 + ... + 8419104039.

It is an arithmetic number, because the mean of its divisors is an integer number (1547553280).

Almost surely, 2^665109216000 is an apocalyptic number.

665109216000 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 665109216000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1337086033920).

665109216000 is an abundant number, since it is smaller than the sum of its proper divisors (2009062851840).

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

665109216000 is a wasteful number, since it uses less digits than its factorization.

665109216000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The spelling of 665109216000 in words is "six hundred sixty-five billion, one hundred nine million, two hundred sixteen thousand".