21012212222120 has 256 divisors, whose sum is σ = 56991162470400. Its totient is φ = 6816526295040.

The previous prime is 21012212222119. The next prime is 21012212222129. The reversal of 21012212222120 is 2122221221012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21012212222092 and 21012212222101.

It is not an unprimeable number, because it can be changed into a prime (21012212222129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 476132216 + ... + 476176344.

It is an arithmetic number, because the mean of its divisors is an integer number (222621728400).

Almost surely, 2^{21012212222120} is an apocalyptic number.

21012212222120 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 21012212222120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28495581235200).

21012212222120 is an abundant number, since it is smaller than the sum of its proper divisors (35978950248280).

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

21012212222120 is a wasteful number, since it uses less digits than its factorization.

21012212222120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44968 (or 44964 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21012212222120 its reverse (2122221221012), we get a palindrome (23134433443132).

The spelling of 21012212222120 in words is "twenty-one trillion, twelve billion, two hundred twelve million, two hundred twenty-two thousand, one hundred twenty".