221553326464 has 64 divisors (see below), whose sum is σ = 446485934160. Its totient is φ = 109496991744.

The previous prime is 221553326443. The next prime is 221553326483. The reversal of 221553326464 is 464623355122.

221553326464 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 221553326464.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10257244 + ... + 10278820.

Almost surely, 2^221553326464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221553326464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (223242967080).

221553326464 is an abundant number, since it is smaller than the sum of its proper divisors (224932607696).

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

221553326464 is an equidigital number, since it uses as much as digits as its factorization.

221553326464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22515 (or 22503 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 43.

The spelling of 221553326464 in words is "two hundred twenty-one billion, five hundred fifty-three million, three hundred twenty-six thousand, four hundred sixty-four".