21212122022220 has 48 divisors (see below), whose sum is σ = 62887702939488. Its totient is φ = 5323826703360.

The previous prime is 21212122022197. The next prime is 21212122022239. The reversal of 21212122022220 is 2222022121212.

It is an unprimeable number.

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, 10398098011 + ... + 10398100050.

It is an arithmetic number, because the mean of its divisors is an integer number (1310160477906).

Almost surely, 2^{21212122022220} is an apocalyptic number.

21212122022220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212122022220 is an abundant number, since it is smaller than the sum of its proper divisors (41675580917268).

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

21212122022220 is a wasteful number, since it uses less digits than its factorization.

21212122022220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20796198090 (or 20796198088 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21212122022220 its reverse (2222022121212), we get a palindrome (23434144143432).

The spelling of 21212122022220 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-two million, twenty-two thousand, two hundred twenty".