665205528 has 128 divisors (see below), whose sum is σ = 1849478400. Its totient is φ = 198084096.

The previous prime is 665205521. The next prime is 665205539. The reversal of 665205528 is 825502566.

It is a happy number.

665205528 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665205521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2401326 + ... + 2401602.

It is an arithmetic number, because the mean of its divisors is an integer number (14449050).

Almost surely, 2^665205528 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 665205528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (924739200).

665205528 is an abundant number, since it is smaller than the sum of its proper divisors (1184272872).

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

665205528 is a wasteful number, since it uses less digits than its factorization.

665205528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 39.

The square root of 665205528 is about 25791.5786255902. The cubic root of 665205528 is about 872.9417868126.

The spelling of 665205528 in words is "six hundred sixty-five million, two hundred five thousand, five hundred twenty-eight".