16221632556 has 48 divisors (see below), whose sum is σ = 39599529984. Its totient is φ = 5158576896.

The previous prime is 16221632551. The next prime is 16221632587. The reversal of 16221632556 is 65523612261.

16221632556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (16221632551) by changing a digit.

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, 28980 + ... + 182436.

It is an arithmetic number, because the mean of its divisors is an integer number (824990208).

Almost surely, 2^16221632556 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 16221632556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19799764992).

16221632556 is an abundant number, since it is smaller than the sum of its proper divisors (23377897428).

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

16221632556 is a wasteful number, since it uses less digits than its factorization.

16221632556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153870 (or 153868 counting only the distinct ones).

The product of its digits is 129600, while the sum is 39.

The spelling of 16221632556 in words is "sixteen billion, two hundred twenty-one million, six hundred thirty-two thousand, five hundred fifty-six".