221221110 has 64 divisors (see below), whose sum is σ = 585252864. Its totient is φ = 53068800.

The previous prime is 221221097. The next prime is 221221127. The reversal of 221221110 is 11122122.

221221110 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 31 ways as a sum of consecutive naturals, for example, 28555 + ... + 35465.

It is an arithmetic number, because the mean of its divisors is an integer number (9144576).

Almost surely, 2^221221110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221221110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292626432).

221221110 is an abundant number, since it is smaller than the sum of its proper divisors (364031754).

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

221221110 is a wasteful number, since it uses less digits than its factorization.

221221110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7029.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 221221110 is about 14873.5036222136. The cubic root of 221221110 is about 604.7959241575.

Adding to 221221110 its reverse (11122122), we get a palindrome (232343232).

It can be divided in two parts, 22122 and 1110, that added together give a palindrome (23232).

The spelling of 221221110 in words is "two hundred twenty-one million, two hundred twenty-one thousand, one hundred ten".