6645543216 has 40 divisors (see below), whose sum is σ = 18488243760. Its totient is φ = 2044782336.

The previous prime is 6645543209. The next prime is 6645543241. The reversal of 6645543216 is 6123455466.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5324331 + ... + 5325578.

It is an arithmetic number, because the mean of its divisors is an integer number (462206094).

Almost surely, 2^6645543216 is an apocalyptic number.

It is an amenable number.

6645543216 is an abundant number, since it is smaller than the sum of its proper divisors (11842700544).

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

6645543216 is a wasteful number, since it uses less digits than its factorization.

6645543216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10649933 (or 10649927 counting only the distinct ones).

The product of its digits is 518400, while the sum is 42.

The square root of 6645543216 is about 81520.2012755121. The cubic root of 6645543216 is about 1880.0821617933.

The spelling of 6645543216 in words is "six billion, six hundred forty-five million, five hundred forty-three thousand, two hundred sixteen".