221230011220 has 72 divisors (see below), whose sum is σ = 486116928360. Its totient is φ = 84564986880.

The previous prime is 221230011187. The next prime is 221230011271. The reversal of 221230011220 is 22110032122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 38924922436 + 182305088784 = 197294^2 + 426972^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221230011194 and 221230011203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11935560 + ... + 11954080.

It is an arithmetic number, because the mean of its divisors is an integer number (6751624005).

Almost surely, 2^221230011220 is an apocalyptic number.

221230011220 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 221230011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243058464180).

221230011220 is an abundant number, since it is smaller than the sum of its proper divisors (264886917140).

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

221230011220 is a wasteful number, since it uses less digits than its factorization.

221230011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19705 (or 19680 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 221230011220 its reverse (22110032122), we get a palindrome (243340043342).

The spelling of 221230011220 in words is "two hundred twenty-one billion, two hundred thirty million, eleven thousand, two hundred twenty".