221559228 has 108 divisors (see below), whose sum is σ = 648236680. Its totient is φ = 63581760.

The previous prime is 221559223. The next prime is 221559257. The reversal of 221559228 is 822955122.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 221559192 and 221559201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221559223) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 81426 + ... + 84102.

Almost surely, 2^221559228 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 221559228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324118340).

221559228 is an abundant number, since it is smaller than the sum of its proper divisors (426677452).

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

221559228 is a wasteful number, since it uses less digits than its factorization.

221559228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2728 (or 2712 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 221559228 is about 14884.8657367139. The cubic root of 221559228 is about 605.1038940034.

The spelling of 221559228 in words is "two hundred twenty-one million, five hundred fifty-nine thousand, two hundred twenty-eight".