6661663560 has 80 divisors (see below), whose sum is σ = 22390602300. Its totient is φ = 1776442752.

The previous prime is 6661663523. The next prime is 6661663577. The reversal of 6661663560 is 653661666.

It can be written as a sum of positive squares in 2 ways, for example, as 6349858596 + 311804964 = 79686^2 + 17658^2 .

It is a super-2 number, since 2×6661663560² = 88755522773263747200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1024795 + ... + 1031274.

Almost surely, 2^6661663560 is an apocalyptic number.

6661663560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6661663560 is an abundant number, since it is smaller than the sum of its proper divisors (15728938740).

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

6661663560 is a wasteful number, since it uses less digits than its factorization.

6661663560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056092 (or 2056079 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 45.

The square root of 6661663560 is about 81619.0146963316. The cubic root of 6661663560 is about 1881.6011295742.

The spelling of 6661663560 in words is "six billion, six hundred sixty-one million, six hundred sixty-three thousand, five hundred sixty".