6561784313604 has 567 divisors, whose sum is σ = 19325969992749. Its totient is φ = 1947634191360.

The previous prime is 6561784313573. The next prime is 6561784313633. The reversal of 6561784313604 is 4063134871656.

The square root of 6561784313604 is 2561598.

It is a perfect power (a square), and thus also a powerful number.

6561784313604 is a `hidden beast` number, since 6 + 5 + 6 + 17 + 8 + 4 + 3 + 13 + 604 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 5047526088900 + 1514258224704 = 2246670^2 + 1230552^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 188 ways as a sum of consecutive naturals, for example, 73727913592 + ... + 73727913680.

Almost surely, 2^{6561784313604} is an apocalyptic number.

6561784313604 is the 2561598-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6561784313604

6561784313604 is an abundant number, since it is smaller than the sum of its proper divisors (12764185679145).

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

6561784313604 is an equidigital number, since it uses as much as digits as its factorization.

6561784313604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 54.

The spelling of 6561784313604 in words is "six trillion, five hundred sixty-one billion, seven hundred eighty-four million, three hundred thirteen thousand, six hundred four".