6565805568 has 420 divisors, whose sum is σ = 22944212280. Its totient is φ = 1870718976.

The previous prime is 6565805563. The next prime is 6565805591. The reversal of 6565805568 is 8655085656.

6565805568 is a `hidden beast` number, since 6 + 5 + 6 + 5 + 80 + 556 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6565805563) by changing a digit.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 18288973 + ... + 18289331.

Almost surely, 2^6565805568 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 6565805568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11472106140).

6565805568 is an abundant number, since it is smaller than the sum of its proper divisors (16378406712).

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

6565805568 is an frugal number, since it uses more digits than its factorization.

6565805568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 8640000, while the sum is 54.

The square root of 6565805568 is about 81029.6585701803. The cubic root of 6565805568 is about 1872.5323929529.

The spelling of 6565805568 in words is "six billion, five hundred sixty-five million, eight hundred five thousand, five hundred sixty-eight".