665600320 has 336 divisors, whose sum is σ = 2139037632. Its totient is φ = 194396160.

The previous prime is 665600297. The next prime is 665600321. The reversal of 665600320 is 23006566.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665600321) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 2932047 + ... + 2932273.

Almost surely, 2^665600320 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 665600320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1069518816).

665600320 is an abundant number, since it is smaller than the sum of its proper divisors (1473437312).

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

665600320 is a wasteful number, since it uses less digits than its factorization.

665600320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286 (or 269 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 28.

The square root of 665600320 is about 25799.2309962913. The cubic root of 665600320 is about 873.1144463710.

Adding to 665600320 its reverse (23006566), we get a palindrome (688606886).

The spelling of 665600320 in words is "six hundred sixty-five million, six hundred thousand, three hundred twenty".