665560520 has 32 divisors (see below), whose sum is σ = 1502263800. Its totient is φ = 265379328.

The previous prime is 665560517. The next prime is 665560531. The reversal of 665560520 is 25065566.

It can be written as a sum of positive squares in 4 ways, for example, as 243422404 + 422138116 = 15602^2 + 20546^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13565 + ... + 38924.

Almost surely, 2^665560520 is an apocalyptic number.

It is an amenable number.

665560520 is an abundant number, since it is smaller than the sum of its proper divisors (836703280).

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

665560520 is a wasteful number, since it uses less digits than its factorization.

665560520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52817 (or 52813 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 35.

The square root of 665560520 is about 25798.4596439400. The cubic root of 665560520 is about 873.0970432105.

The spelling of 665560520 in words is "six hundred sixty-five million, five hundred sixty thousand, five hundred twenty".