221980656 has 80 divisors (see below), whose sum is σ = 589605120. Its totient is φ = 71938560.

The previous prime is 221980631. The next prime is 221980657. The reversal of 221980656 is 656089122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221980657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 291316 + ... + 292076.

It is an arithmetic number, because the mean of its divisors is an integer number (7370064).

Almost surely, 2^221980656 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 221980656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294802560).

221980656 is an abundant number, since it is smaller than the sum of its proper divisors (367624464).

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

221980656 is a wasteful number, since it uses less digits than its factorization.

221980656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 934 (or 928 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 221980656 is about 14899.0152694733. The cubic root of 221980656 is about 605.4873072233.

The spelling of 221980656 in words is "two hundred twenty-one million, nine hundred eighty thousand, six hundred fifty-six".