6543221509 has 4 divisors (see below), whose sum is σ = 7138059840. Its totient is φ = 5948383180.

The previous prime is 6543221497. The next prime is 6543221533. The reversal of 6543221509 is 9051223456.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6543221509 - 2⁷ = 6543221381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6543221609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 297419149 + ... + 297419170.

It is an arithmetic number, because the mean of its divisors is an integer number (1784514960).

Almost surely, 2^6543221509 is an apocalyptic number.

It is an amenable number.

6543221509 is a deficient number, since it is larger than the sum of its proper divisors (594838331).

6543221509 is a wasteful number, since it uses less digits than its factorization.

6543221509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594838330.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 6543221509 is about 80890.1817836998. The cubic root of 6543221509 is about 1870.3829759808.

The spelling of 6543221509 in words is "six billion, five hundred forty-three million, two hundred twenty-one thousand, five hundred nine".