221089820 has 48 divisors (see below), whose sum is σ = 535610880. Its totient is φ = 75088704.

The previous prime is 221089793. The next prime is 221089831. The reversal of 221089820 is 28980122.

221089820 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7601 + ... + 22359.

It is an arithmetic number, because the mean of its divisors is an integer number (11158560).

Almost surely, 2^221089820 is an apocalyptic number.

221089820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221089820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267805440).

221089820 is an abundant number, since it is smaller than the sum of its proper divisors (314521060).

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

221089820 is a wasteful number, since it uses less digits than its factorization.

221089820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14882 (or 14880 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 221089820 is about 14869.0894139487. The cubic root of 221089820 is about 604.6762559966.

The spelling of 221089820 in words is "two hundred twenty-one million, eighty-nine thousand, eight hundred twenty".