21012220120221 has 24 divisors (see below), whose sum is σ = 34336467451104. Its totient is φ = 12734678859120.

The previous prime is 21012220120207. The next prime is 21012220120273. The reversal of 21012220120221 is 12202102221012.

It is a happy number.

21012220120221 is a `hidden beast` number, since 2 + 101 + 2 + 220 + 120 + 221 = 666.

It is not a de Polignac number, because 21012220120221 - 2¹¹ = 21012220118173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012220120194 and 21012220120203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012220120201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3930453766 + ... + 3930459111.

It is an arithmetic number, because the mean of its divisors is an integer number (1430686143796).

Almost surely, 2^{21012220120221} is an apocalyptic number.

It is an amenable number.

21012220120221 is a deficient number, since it is larger than the sum of its proper divisors (13324247330883).

21012220120221 is an equidigital number, since it uses as much as digits as its factorization.

21012220120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7860912903 (or 7860912891 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21012220120221 its reverse (12202102221012), we get a palindrome (33214322341233).

The spelling of 21012220120221 in words is "twenty-one trillion, twelve billion, two hundred twenty million, one hundred twenty thousand, two hundred twenty-one".