21212211220121 has 8 divisors (see below), whose sum is σ = 21339485463744. Its totient is φ = 21084940012720.

The previous prime is 21212211220103. The next prime is 21212211220171. The reversal of 21212211220121 is 12102211221212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21212211220121 - 2¹⁰ = 21212211219097 is a prime.

It is a super-3 number, since 3×21212211220121³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21212211220093 and 21212211220102.

It is not an unprimeable number, because it can be changed into a prime (21212211220171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14128931 + ... + 15557991.

It is an arithmetic number, because the mean of its divisors is an integer number (2667435682968).

Almost surely, 2^{21212211220121} is an apocalyptic number.

It is an amenable number.

21212211220121 is a deficient number, since it is larger than the sum of its proper divisors (127274243623).

21212211220121 is a wasteful number, since it uses less digits than its factorization.

21212211220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1518111.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21212211220121 its reverse (12102211221212), we get a palindrome (33314422441333).

The spelling of 21212211220121 in words is "twenty-one trillion, two hundred twelve billion, two hundred eleven million, two hundred twenty thousand, one hundred twenty-one".