6561711936 has 224 divisors, whose sum is σ = 21260328320. Its totient is φ = 1971744768.

The previous prime is 6561711931. The next prime is 6561711991. The reversal of 6561711936 is 6391171656.

6561711936 is a `hidden beast` number, since 6 + 561 + 71 + 19 + 3 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 6561711891 and 6561711900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561711931) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 962556 + ... + 969348.

It is an arithmetic number, because the mean of its divisors is an integer number (94912180).

Almost surely, 2^6561711936 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6561711936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10630164160).

6561711936 is an abundant number, since it is smaller than the sum of its proper divisors (14698616384).

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

6561711936 is a wasteful number, since it uses less digits than its factorization.

6561711936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6870 (or 6854 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 6561711936 is about 81004.3945474565. The cubic root of 6561711936 is about 1872.1431514461.

The spelling of 6561711936 in words is "six billion, five hundred sixty-one million, seven hundred eleven thousand, nine hundred thirty-six".