665020 has 24 divisors (see below), whose sum is σ = 1432368. Its totient is φ = 259200.

The previous prime is 665017. The next prime is 665029. The reversal of 665020 is 20566.

665020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 415 + ... + 1225.

It is an arithmetic number, because the mean of its divisors is an integer number (59682).

2⁶⁶⁵⁰²⁰ 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 665020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (716184).

665020 is an abundant number, since it is smaller than the sum of its proper divisors (767348).

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

665020 is a wasteful number, since it uses less digits than its factorization.

665020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861 (or 859 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 665020 is about 815.4875842096. The cubic root of 665020 is about 87.2860623826.

Adding to 665020 its reverse (20566), we get a palindrome (685586).

It can be divided in two parts, 6650 and 20, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 665020 in words is "six hundred sixty-five thousand, twenty".