665878280 has 32 divisors (see below), whose sum is σ = 1549891800. Its totient is φ = 257166336.

The previous prime is 665878277. The next prime is 665878289. The reversal of 665878280 is 82878566.

665878280 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 492218596 + 173659684 = 22186^2 + 13178^2 .

It is not an unprimeable number, because it can be changed into a prime (665878289) 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, 285857 + ... + 288176.

Almost surely, 2^665878280 is an apocalyptic number.

It is an amenable number.

665878280 is an abundant number, since it is smaller than the sum of its proper divisors (884013520).

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

665878280 is a wasteful number, since it uses less digits than its factorization.

665878280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574073 (or 574069 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 50.

The square root of 665878280 is about 25804.6174162687. The cubic root of 665878280 is about 873.2359693075.

The spelling of 665878280 in words is "six hundred sixty-five million, eight hundred seventy-eight thousand, two hundred eighty".