665207120 has 20 divisors (see below), whose sum is σ = 1546606740. Its totient is φ = 266082816.

The previous prime is 665207113. The next prime is 665207129. The reversal of 665207120 is 21702566.

It can be written as a sum of positive squares in 2 ways, for example, as 141895744 + 523311376 = 11912^2 + 22876^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665207129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4157465 + ... + 4157624.

It is an arithmetic number, because the mean of its divisors is an integer number (77330337).

Almost surely, 2^665207120 is an apocalyptic number.

It is an amenable number.

665207120 is an abundant number, since it is smaller than the sum of its proper divisors (881399620).

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

665207120 is a wasteful number, since it uses less digits than its factorization.

665207120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8315102 (or 8315096 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 665207120 is about 25791.6094883588. The cubic root of 665207120 is about 872.9424831999.

Adding to 665207120 its reverse (21702566), we get a palindrome (686909686).

The spelling of 665207120 in words is "six hundred sixty-five million, two hundred seven thousand, one hundred twenty".