21002120022220 has 96 divisors (see below), whose sum is σ = 46533546662400. Its totient is φ = 7946414598144.

The previous prime is 21002120022193. The next prime is 21002120022241. The reversal of 21002120022220 is 2222002120012.

It is a junction number, because it is equal to n+sod(n) for n = 21002120022194 and 21002120022203.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55989651 + ... + 56363509.

It is an arithmetic number, because the mean of its divisors is an integer number (484724444400).

Almost surely, 2^{21002120022220} is an apocalyptic number.

21002120022220 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 21002120022220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23266773331200).

21002120022220 is an abundant number, since it is smaller than the sum of its proper divisors (25531426640180).

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

21002120022220 is a wasteful number, since it uses less digits than its factorization.

21002120022220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375247 (or 375245 counting only the distinct ones).

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

Adding to 21002120022220 its reverse (2222002120012), we get a palindrome (23224122142232).

The spelling of 21002120022220 in words is "twenty-one trillion, two billion, one hundred twenty million, twenty-two thousand, two hundred twenty".