665608320 has 256 divisors, whose sum is σ = 2539555200. Its totient is φ = 163786752.

The previous prime is 665608303. The next prime is 665608369. The reversal of 665608320 is 23806566.

665608320 is a `hidden beast` number, since 66 + 560 + 8 + 32 + 0 = 666.

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

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 31 ways as a sum of consecutive naturals, for example, 223159 + ... + 226121.

Almost surely, 2^665608320 is an apocalyptic number.

665608320 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 665608320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1269777600).

665608320 is an abundant number, since it is smaller than the sum of its proper divisors (1873946880).

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

665608320 is a wasteful number, since it uses less digits than its factorization.

665608320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3004 (or 2986 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 665608320 is about 25799.3860392064. The cubic root of 665608320 is about 873.1179444100.

The spelling of 665608320 in words is "six hundred sixty-five million, six hundred eight thousand, three hundred twenty".