21212000121220 has 12 divisors (see below), whose sum is σ = 44545200254604. Its totient is φ = 8484800048480.

The previous prime is 21212000121217. The next prime is 21212000121223. The reversal of 21212000121220 is 2212100021212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21212000121217) and next prime (21212000121223).

It can be written as a sum of positive squares in 2 ways, for example, as 15194045386116 + 6017954735104 = 3897954^2 + 2453152^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21212000121194 and 21212000121203.

It is not an unprimeable number, because it can be changed into a prime (21212000121223) 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 3 ways as a sum of consecutive naturals, for example, 530300003011 + ... + 530300003050.

It is an arithmetic number, because the mean of its divisors is an integer number (3712100021217).

Almost surely, 2^{21212000121220} is an apocalyptic number.

21212000121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212000121220 is an abundant number, since it is smaller than the sum of its proper divisors (23333200133384).

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

21212000121220 is a wasteful number, since it uses less digits than its factorization.

21212000121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060600006070 (or 1060600006068 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21212000121220 its reverse (2212100021212), we get a palindrome (23424100142432).

The spelling of 21212000121220 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-one thousand, two hundred twenty".