665340660 has 72 divisors (see below), whose sum is σ = 2072766696. Its totient is φ = 172627200.

The previous prime is 665340647. The next prime is 665340667. The reversal of 665340660 is 66043566.

665340660 is a `hidden beast` number, since 66 + 534 + 0 + 6 + 60 = 666.

665340660 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 381889764 + 283450896 = 19542^2 + 16836^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665340667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43291 + ... + 56610.

Almost surely, 2^665340660 is an apocalyptic number.

665340660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665340660 is an abundant number, since it is smaller than the sum of its proper divisors (1407426036).

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

665340660 is a wasteful number, since it uses less digits than its factorization.

665340660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99953 (or 99948 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 665340660 is about 25794.1981848632. The cubic root of 665340660 is about 873.0008935486. Note that the first 3 decimals are identical.

The spelling of 665340660 in words is "six hundred sixty-five million, three hundred forty thousand, six hundred sixty".