21220022002120 has 64 divisors (see below), whose sum is σ = 50620364538480. Its totient is φ = 7978160848896.

The previous prime is 21220022002079. The next prime is 21220022002129. The reversal of 21220022002120 is 2120022002212.

It can be written as a sum of positive squares in 8 ways, for example, as 19437887780964 + 1782134221156 = 4408842^2 + 1334966^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21220022002094 and 21220022002103.

It is not an unprimeable number, because it can be changed into a prime (21220022002129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20096809 + ... + 21126328.

Almost surely, 2^{21220022002120} is an apocalyptic number.

21220022002120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220022002120 is an abundant number, since it is smaller than the sum of its proper divisors (29400342536360).

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

21220022002120 is a wasteful number, since it uses less digits than its factorization.

21220022002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41223922 (or 41223918 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21220022002120 its reverse (2120022002212), we get a palindrome (23340044004332).

The spelling of 21220022002120 in words is "twenty-one trillion, two hundred twenty billion, twenty-two million, two thousand, one hundred twenty".