665533520 has 80 divisors (see below), whose sum is σ = 1699712640. Its totient is φ = 241224192.

The previous prime is 665533483. The next prime is 665533523. The reversal of 665533520 is 25335566.

665533520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665533523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25442 + ... + 44478.

It is an arithmetic number, because the mean of its divisors is an integer number (21246408).

Almost surely, 2^665533520 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 665533520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (849856320).

665533520 is an abundant number, since it is smaller than the sum of its proper divisors (1034179120).

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

665533520 is a wasteful number, since it uses less digits than its factorization.

665533520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19092 (or 19086 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 35.

The square root of 665533520 is about 25797.9363515767. The cubic root of 665533520 is about 873.0852366514.

The spelling of 665533520 in words is "six hundred sixty-five million, five hundred thirty-three thousand, five hundred twenty".