665530320 has 320 divisors, whose sum is σ = 2623832064. Its totient is φ = 135751680.

The previous prime is 665530301. The next prime is 665530321. The reversal of 665530320 is 23035566.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665530321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 676549 + ... + 677531.

Almost surely, 2^665530320 is an apocalyptic number.

665530320 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 665530320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1311916032).

665530320 is an abundant number, since it is smaller than the sum of its proper divisors (1958301744).

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

665530320 is a wasteful number, since it uses less digits than its factorization.

665530320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050 (or 1044 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 30.

The square root of 665530320 is about 25797.8743310374. The cubic root of 665530320 is about 873.0838373343.

Adding to 665530320 its reverse (23035566), we get a palindrome (688565886).

The spelling of 665530320 in words is "six hundred sixty-five million, five hundred thirty thousand, three hundred twenty".