665720000 has 280 divisors, whose sum is σ = 1928195280. Its totient is φ = 225280000.

The previous prime is 665719979. The next prime is 665720047. The reversal of 665720000 is 27566.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 7479956 + ... + 7480044.

Almost surely, 2^665720000 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 665720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (964097640).

665720000 is an abundant number, since it is smaller than the sum of its proper divisors (1262475280).

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

665720000 is a wasteful number, since it uses less digits than its factorization.

665720000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 665720000 is about 25801.5503410163. The cubic root of 665720000 is about 873.1667741076.

Adding to 665720000 its reverse (27566), we get a palindrome (665747566).

The spelling of 665720000 in words is "six hundred sixty-five million, seven hundred twenty thousand".