6561776200 has 144 divisors (see below), whose sum is σ = 18320256000. Its totient is φ = 2177078400.

The previous prime is 6561776189. The next prime is 6561776209. The reversal of 6561776200 is 26771656.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (6561776209) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 293001 + ... + 314599.

It is an arithmetic number, because the mean of its divisors is an integer number (127224000).

Almost surely, 2^6561776200 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 6561776200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9160128000).

6561776200 is an abundant number, since it is smaller than the sum of its proper divisors (11758479800).

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

6561776200 is a wasteful number, since it uses less digits than its factorization.

6561776200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21660 (or 21644 counting only the distinct ones).

The product of its (nonzero) digits is 105840, while the sum is 40.

The square root of 6561776200 is about 81004.7912163225. The cubic root of 6561776200 is about 1872.1492632157.

The spelling of 6561776200 in words is "six billion, five hundred sixty-one million, seven hundred seventy-six thousand, two hundred".