21001220022220 has 48 divisors (see below), whose sum is σ = 46698054046560. Its totient is φ = 7906134477824.

The previous prime is 21001220022187. The next prime is 21001220022221. The reversal of 21001220022220 is 2222002210012.

It is a junction number, because it is equal to n+sod(n) for n = 21001220022194 and 21001220022203.

It is not an unprimeable number, because it can be changed into a prime (21001220022221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12506646 + ... + 14086114.

It is an arithmetic number, because the mean of its divisors is an integer number (972876125970).

Almost surely, 2^{21001220022220} is an apocalyptic number.

21001220022220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001220022220 is an abundant number, since it is smaller than the sum of its proper divisors (25696834024340).

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

21001220022220 is a wasteful number, since it uses less digits than its factorization.

21001220022220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618602 (or 1618600 counting only the distinct ones).

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

Adding to 21001220022220 its reverse (2222002210012), we get a palindrome (23223222232232).

The spelling of 21001220022220 in words is "twenty-one trillion, one billion, two hundred twenty million, twenty-two thousand, two hundred twenty".