21212020112221 has 16 divisors (see below), whose sum is σ = 21939782860800. Its totient is φ = 20499983103600.

The previous prime is 21212020112209. The next prime is 21212020112237. The reversal of 21212020112221 is 12221102021212.

It is a cyclic number.

It is not a de Polignac number, because 21212020112221 - 2¹³ = 21212020104029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212020112251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12823885 + ... + 14383186.

It is an arithmetic number, because the mean of its divisors is an integer number (1371236428800).

Almost surely, 2^{21212020112221} is an apocalyptic number.

It is an amenable number.

21212020112221 is a deficient number, since it is larger than the sum of its proper divisors (727762748579).

21212020112221 is a wasteful number, since it uses less digits than its factorization.

21212020112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27207360.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21212020112221 its reverse (12221102021212), we get a palindrome (33433122133433).

The spelling of 21212020112221 in words is "twenty-one trillion, two hundred twelve billion, twenty million, one hundred twelve thousand, two hundred twenty-one".