21212021302221 has 24 divisors (see below), whose sum is σ = 29465940411264. Its totient is φ = 13570667268480.

The previous prime is 21212021302211. The next prime is 21212021302231. The reversal of 21212021302221 is 12220312021212.

It is an interprime number because it is at equal distance from previous prime (21212021302211) and next prime (21212021302231).

It is not a de Polignac number, because 21212021302221 - 2²⁹ = 21211484431309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212021302211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35075845 + ... + 35675466.

It is an arithmetic number, because the mean of its divisors is an integer number (1227747517136).

Almost surely, 2^{21212021302221} is an apocalyptic number.

It is an amenable number.

21212021302221 is a deficient number, since it is larger than the sum of its proper divisors (8253919109043).

21212021302221 is an equidigital number, since it uses as much as digits as its factorization.

21212021302221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70751461 (or 70751424 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21212021302221 its reverse (12220312021212), we get a palindrome (33432333323433).

The spelling of 21212021302221 in words is "twenty-one trillion, two hundred twelve billion, twenty-one million, three hundred two thousand, two hundred twenty-one".