665120 has 24 divisors (see below), whose sum is σ = 1571724. Its totient is φ = 265984.

The previous prime is 665117. The next prime is 665123. The reversal of 665120 is 21566.

It is an interprime number because it is at equal distance from previous prime (665117) and next prime (665123).

It can be written as a sum of positive squares in 2 ways, for example, as 659344 + 5776 = 812^2 + 76^2 .

It is a super-2 number, since 2×665120² = 884769228800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 665092 and 665101.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665120.

It is not an unprimeable number, because it can be changed into a prime (665123) 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, 1919 + ... + 2238.

2⁶⁶⁵¹²⁰ is an apocalyptic number.

It is an amenable number.

665120 is an abundant number, since it is smaller than the sum of its proper divisors (906604).

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

665120 is a wasteful number, since it uses less digits than its factorization.

665120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4172 (or 4164 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 665120 is about 815.5488949168. The cubic root of 665120 is about 87.2904372729.

Adding to 665120 its reverse (21566), we get a palindrome (686686).

It can be divided in two parts, 665 and 120, that multiplied together give a triangular number (79800 = T₃₉₉).

The spelling of 665120 in words is "six hundred sixty-five thousand, one hundred twenty".