665516020 has 24 divisors (see below), whose sum is σ = 1505090664. Its totient is φ = 245728896.

The previous prime is 665516011. The next prime is 665516023. The reversal of 665516020 is 20615566.

It can be written as a sum of positive squares in 4 ways, for example, as 4717584 + 660798436 = 2172^2 + 25706^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665516023) 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, 1279579 + ... + 1280098.

It is an arithmetic number, because the mean of its divisors is an integer number (62712111).

Almost surely, 2^665516020 is an apocalyptic number.

It is an amenable number.

665516020 is an abundant number, since it is smaller than the sum of its proper divisors (839574644).

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

665516020 is a wasteful number, since it uses less digits than its factorization.

665516020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2559699 (or 2559697 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 665516020 is about 25797.5971749308. The cubic root of 665516020 is about 873.0775840814.

The spelling of 665516020 in words is "six hundred sixty-five million, five hundred sixteen thousand, twenty".