221644535663 has 24 divisors (see below), whose sum is σ = 240526519200. Its totient is φ = 204125178816.

The previous prime is 221644535621. The next prime is 221644535669. The reversal of 221644535663 is 366535446122.

It is not a de Polignac number, because 221644535663 - 2³² = 217349568367 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 (221644535669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2032358 + ... + 2138636.

It is an arithmetic number, because the mean of its divisors is an integer number (10021938300).

Almost surely, 2^221644535663 is an apocalyptic number.

221644535663 is a deficient number, since it is larger than the sum of its proper divisors (18881983537).

221644535663 is a wasteful number, since it uses less digits than its factorization.

221644535663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106479 (or 106460 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 47.

The spelling of 221644535663 in words is "two hundred twenty-one billion, six hundred forty-four million, five hundred thirty-five thousand, six hundred sixty-three".