21121110012221 has 8 divisors (see below), whose sum is σ = 22580649883584. Its totient is φ = 19685694767040.

The previous prime is 21121110012209. The next prime is 21121110012239. The reversal of 21121110012221 is 12221001112112.

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

It is not a de Polignac number, because 21121110012221 - 2⁶ = 21121110012157 is a prime.

It is a super-2 number, since 2×21121110012221² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121110012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121110012251) 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, 6031154735 + ... + 6031158236.

It is an arithmetic number, because the mean of its divisors is an integer number (2822581235448).

Almost surely, 2^{21121110012221} is an apocalyptic number.

It is an amenable number.

21121110012221 is a deficient number, since it is larger than the sum of its proper divisors (1459539871363).

21121110012221 is a wasteful number, since it uses less digits than its factorization.

21121110012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12062313091.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21121110012221 its reverse (12221001112112), we get a palindrome (33342111124333).

The spelling of 21121110012221 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred ten million, twelve thousand, two hundred twenty-one".