665111620 has 12 divisors (see below), whose sum is σ = 1396734444. Its totient is φ = 266044640.

The previous prime is 665111591. The next prime is 665111627. The reversal of 665111620 is 26111566.

It can be written as a sum of positive squares in 2 ways, for example, as 80245764 + 584865856 = 8958^2 + 24184^2 .

It is not an unprimeable number, because it can be changed into a prime (665111627) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 16627771 + ... + 16627810.

It is an arithmetic number, because the mean of its divisors is an integer number (116394537).

Almost surely, 2^665111620 is an apocalyptic number.

It is an amenable number.

665111620 is an abundant number, since it is smaller than the sum of its proper divisors (731622824).

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

665111620 is a wasteful number, since it uses less digits than its factorization.

665111620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33255590 (or 33255588 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 665111620 is about 25789.7580446192. The cubic root of 665111620 is about 872.9007067394.

The spelling of 665111620 in words is "six hundred sixty-five million, one hundred eleven thousand, six hundred twenty".