21212010120 has 128 divisors (see below), whose sum is σ = 72801066240. Its totient is φ = 4843514880.

The previous prime is 21212010119. The next prime is 21212010133. The reversal of 21212010120 is 2101021212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21212010096 and 21212010105.

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, 845274 + ... + 870006.

It is an arithmetic number, because the mean of its divisors is an integer number (568758330).

Almost surely, 2^21212010120 is an apocalyptic number.

21212010120 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 21212010120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36400533120).

21212010120 is an abundant number, since it is smaller than the sum of its proper divisors (51589056120).

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

21212010120 is a wasteful number, since it uses less digits than its factorization.

21212010120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25775 (or 25771 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21212010120 its reverse (2101021212), we get a palindrome (23313031332).

The spelling of 21212010120 in words is "twenty-one billion, two hundred twelve million, ten thousand, one hundred twenty".