221221104 has 160 divisors (see below), whose sum is σ = 663290880. Its totient is φ = 62954496.

The previous prime is 221221097. The next prime is 221221127. The reversal of 221221104 is 401122122.

221221104 is digitally balanced in base 2, 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, 557034 + ... + 557430.

It is an arithmetic number, because the mean of its divisors is an integer number (4145568).

Almost surely, 2^221221104 is an apocalyptic number.

221221104 is a gapful number since it is divisible by the number (24) 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 221221104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331645440).

221221104 is an abundant number, since it is smaller than the sum of its proper divisors (442069776).

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

221221104 is a wasteful number, since it uses less digits than its factorization.

221221104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487 (or 481 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 221221104 is about 14873.5034205126. The cubic root of 221221104 is about 604.7959186897.

Adding to 221221104 its reverse (401122122), we get a palindrome (622343226).

The spelling of 221221104 in words is "two hundred twenty-one million, two hundred twenty-one thousand, one hundred four".