221220110021020 has 288 divisors, whose sum is σ = 526985267941440. Its totient is φ = 77352330240000.

The previous prime is 221220110020979. The next prime is 221220110021041. The reversal of 221220110021020 is 20120011022122.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 221220110020985 and 221220110021003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 17308507030 + ... + 17308519810.

It is an arithmetic number, because the mean of its divisors is an integer number (1829809958130).

Almost surely, 2^{221220110021020} is an apocalyptic number.

221220110021020 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 221220110021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263492633970720).

221220110021020 is an abundant number, since it is smaller than the sum of its proper divisors (305765157920420).

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

221220110021020 is a wasteful number, since it uses less digits than its factorization.

221220110021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13545 (or 13506 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221220110021020 its reverse (20120011022122), we get a palindrome (241340121043142).

It can be divided in two parts, 2212201 and 10021020, that added together give a palindrome (12233221).

The spelling of 221220110021020 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred ten million, twenty-one thousand, twenty".