6561065616 has 40 divisors (see below), whose sum is σ = 19370766144. Its totient is φ = 1874590080.

The previous prime is 6561065593. The next prime is 6561065653. The reversal of 6561065616 is 6165601656.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 9763155 + ... + 9763826.

Almost surely, 2^6561065616 is an apocalyptic number.

It is an amenable number.

6561065616 is an abundant number, since it is smaller than the sum of its proper divisors (12809700528).

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

6561065616 is a wasteful number, since it uses less digits than its factorization.

6561065616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19526999 (or 19526993 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 6561065616 is about 81000.4050360244. The cubic root of 6561065616 is about 1872.0816815480.

The spelling of 6561065616 in words is "six billion, five hundred sixty-one million, sixty-five thousand, six hundred sixteen".