6445543566 has 64 divisors (see below), whose sum is σ = 16445822976. Its totient is φ = 1635228000.

The previous prime is 6445543553. The next prime is 6445543571. The reversal of 6445543566 is 6653455446.

It is a super-2 number, since 2×6445543566² = 83090063722407992712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142360 + ... + 182091.

It is an arithmetic number, because the mean of its divisors is an integer number (256965984).

Almost surely, 2^6445543566 is an apocalyptic number.

6445543566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6445543566 is an abundant number, since it is smaller than the sum of its proper divisors (10000279410).

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

6445543566 is a wasteful number, since it uses less digits than its factorization.

6445543566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324517.

The product of its digits is 5184000, while the sum is 48.

The square root of 6445543566 is about 80284.1426808557. The cubic root of 6445543566 is about 1861.0291801084.

The spelling of 6445543566 in words is "six billion, four hundred forty-five million, five hundred forty-three thousand, five hundred sixty-six".