665280 has 224 divisors, whose sum is σ = 2926080. Its totient is φ = 138240.

The previous prime is 665279. The next prime is 665293. The reversal of 665280 is 82566.

665280 = T₁₁₁ + T₁₁₂ + ... + T₁₇₄.

665280 is a `hidden beast` number, since 6 + 652 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665280.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60475 + ... + 60485.

665280 is a highly composite number, because it has more divisors than any smaller number.

665280 is a superabundant number, because it has a larger abundancy index than any smaller number.

2⁶⁶⁵²⁸⁰ is an apocalyptic number.

665280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1463040).

665280 is an abundant number, since it is smaller than the sum of its proper divisors (2260800).

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

665280 is a wasteful number, since it uses less digits than its factorization.

665280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 665280 is about 815.6469824624. The cubic root of 665280 is about 87.2974361855.

665280 divided by its product of nonzero digits (2880) gives a triangular number (231 = T₂₁).

The spelling of 665280 in words is "six hundred sixty-five thousand, two hundred eighty".