665373280 has 144 divisors (see below), whose sum is σ = 1857736944. Its totient is φ = 223242240.

The previous prime is 665373253. The next prime is 665373301. The reversal of 665373280 is 82373566.

It is a super-3 number, since 3×665373280³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 296322 + ... + 298558.

It is an arithmetic number, because the mean of its divisors is an integer number (12900951).

Almost surely, 2^665373280 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 665373280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928868472).

665373280 is an abundant number, since it is smaller than the sum of its proper divisors (1192363664).

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

665373280 is a wasteful number, since it uses less digits than its factorization.

665373280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2289 (or 2268 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 665373280 is about 25794.8304898482. The cubic root of 665373280 is about 873.0151603373.

The spelling of 665373280 in words is "six hundred sixty-five million, three hundred seventy-three thousand, two hundred eighty".