6543221508 has 18 divisors (see below), whose sum is σ = 16539810014. Its totient is φ = 2181073824.

The previous prime is 6543221497. The next prime is 6543221533. The reversal of 6543221508 is 8051223456.

6543221508 is a `hidden beast` number, since 6 + 5 + 432 + 215 + 0 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4800826944 + 1742394564 = 69288^2 + 41742^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 181756153 = 6543221508 / (6 + 5 + 4 + 3 + 2 + 2 + 1 + 5 + 0 + 8).

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, 90878041 + ... + 90878112.

Almost surely, 2^6543221508 is an apocalyptic number.

It is an amenable number.

6543221508 is an abundant number, since it is smaller than the sum of its proper divisors (9996588506).

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

6543221508 is a wasteful number, since it uses less digits than its factorization.

6543221508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181756163 (or 181756158 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 6543221508 is about 80890.1817775186. The cubic root of 6543221508 is about 1870.3829758855.

The spelling of 6543221508 in words is "six billion, five hundred forty-three million, two hundred twenty-one thousand, five hundred eight".