665859168 has 144 divisors (see below), whose sum is σ = 2105341056. Its totient is φ = 198236160.

The previous prime is 665859151. The next prime is 665859203. The reversal of 665859168 is 861958566.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 113196 + ... + 118932.

It is an arithmetic number, because the mean of its divisors is an integer number (14620424).

Almost surely, 2^665859168 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 665859168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1052670528).

665859168 is an abundant number, since it is smaller than the sum of its proper divisors (1439481888).

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

665859168 is a wasteful number, since it uses less digits than its factorization.

665859168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5797 (or 5786 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 54.

The square root of 665859168 is about 25804.2470922908. The cubic root of 665859168 is about 873.2276147047.

The spelling of 665859168 in words is "six hundred sixty-five million, eight hundred fifty-nine thousand, one hundred sixty-eight".