8120784564 has 18 divisors (see below), whose sum is σ = 20527538850. Its totient is φ = 2706928176.

The previous prime is 8120784557. The next prime is 8120784611. The reversal of 8120784564 is 4654870218.

8120784564 is a `hidden beast` number, since 8 + 1 + 2 + 0 + 7 + 84 + 564 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5342440464 + 2778344100 = 73092^2 + 52710^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 112788639 + ... + 112788710.

It is an arithmetic number, because the mean of its divisors is an integer number (1140418825).

Almost surely, 2^8120784564 is an apocalyptic number.

It is an amenable number.

8120784564 is an abundant number, since it is smaller than the sum of its proper divisors (12406754286).

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

8120784564 is a wasteful number, since it uses less digits than its factorization.

8120784564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225577359 (or 225577354 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The square root of 8120784564 is about 90115.3958211359. The cubic root of 8120784564 is about 2010.0151450556.

The spelling of 8120784564 in words is "eight billion, one hundred twenty million, seven hundred eighty-four thousand, five hundred sixty-four".