221501665744 has 80 divisors (see below), whose sum is σ = 448790275584. Its totient is φ = 105780787200.

The previous prime is 221501665643. The next prime is 221501665757. The reversal of 221501665744 is 447566105122.

It is a self number, because there is not a number n which added to its sum of digits gives 221501665744.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54380892 + ... + 54384964.

Almost surely, 2^221501665744 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 221501665744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224395137792).

221501665744 is an abundant number, since it is smaller than the sum of its proper divisors (227288609840).

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

221501665744 is a wasteful number, since it uses less digits than its factorization.

221501665744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5516 (or 5510 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 43.

The spelling of 221501665744 in words is "two hundred twenty-one billion, five hundred one million, six hundred sixty-five thousand, seven hundred forty-four".