665860608 has 240 divisors, whose sum is σ = 2295120960. Its totient is φ = 190052352.

The previous prime is 665860597. The next prime is 665860627. The reversal of 665860608 is 806068566.

665860608 is a `hidden beast` number, since 6 + 6 + 586 + 0 + 60 + 8 = 666.

It is a super-2 number, since 2×665860608² = 886740698572259328, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 676885 + ... + 677867.

It is an arithmetic number, because the mean of its divisors is an integer number (9563004).

Almost surely, 2^665860608 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 665860608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1147560480).

665860608 is an abundant number, since it is smaller than the sum of its proper divisors (1629260352).

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

665860608 is an equidigital number, since it uses as much as digits as its factorization.

665860608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1024 (or 995 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 665860608 is about 25804.2749946593. The cubic root of 665860608 is about 873.2282441906.

The spelling of 665860608 in words is "six hundred sixty-five million, eight hundred sixty thousand, six hundred eight".