21020121201212 has 48 divisors (see below), whose sum is σ = 42268421395200. Its totient is φ = 8959750751232.

The previous prime is 21020121201169. The next prime is 21020121201311. The reversal of 21020121201212 is 21210212102012.

It is a congruent number.

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, 21676523 + ... + 22625469.

It is an arithmetic number, because the mean of its divisors is an integer number (880592112400).

Almost surely, 2^{21020121201212} is an apocalyptic number.

It is an amenable number.

21020121201212 is an abundant number, since it is smaller than the sum of its proper divisors (21248300193988).

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

21020121201212 is a wasteful number, since it uses less digits than its factorization.

21020121201212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953250 (or 953248 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21020121201212 its reverse (21210212102012), we get a palindrome (42230333303224).

The spelling of 21020121201212 in words is "twenty-one trillion, twenty billion, one hundred twenty-one million, two hundred one thousand, two hundred twelve".