21020212122 has 96 divisors (see below), whose sum is σ = 54965162112. Its totient is φ = 5217647616.

The previous prime is 21020212121. The next prime is 21020212159. The reversal of 21020212122 is 22121202012.

It is not an unprimeable number, because it can be changed into a prime (21020212121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 91188 + ... + 224400.

It is an arithmetic number, because the mean of its divisors is an integer number (572553772).

Almost surely, 2^21020212122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020212122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27482581056).

21020212122 is an abundant number, since it is smaller than the sum of its proper divisors (33944949990).

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

21020212122 is a wasteful number, since it uses less digits than its factorization.

21020212122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133272 (or 133255 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020212122 its reverse (22121202012), we get a palindrome (43141414134).

The spelling of 21020212122 in words is "twenty-one billion, twenty million, two hundred twelve thousand, one hundred twenty-two".