6561661160 has 32 divisors (see below), whose sum is σ = 14766108840. Its totient is φ = 2624242944.

The previous prime is 6561661157. The next prime is 6561661181. The reversal of 6561661160 is 611661656.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5744730436 + 816930724 = 75794^2 + 28582^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 395594 + ... + 411846.

Almost surely, 2^6561661160 is an apocalyptic number.

It is an amenable number.

6561661160 is an abundant number, since it is smaller than the sum of its proper divisors (8204447680).

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

6561661160 is a wasteful number, since it uses less digits than its factorization.

6561661160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26357 (or 26353 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 6561661160 is about 81004.0811317553. The cubic root of 6561661160 is about 1872.1383224123.

The spelling of 6561661160 in words is "six billion, five hundred sixty-one million, six hundred sixty-one thousand, one hundred sixty".