21211111201121 has 8 divisors (see below), whose sum is σ = 21405961295400. Its totient is φ = 21016265702400.

The previous prime is 21211111201069. The next prime is 21211111201139. The reversal of 21211111201121 is 12110211111212.

It can be written as a sum of positive squares in 4 ways, for example, as 7466889618721 + 13744221582400 = 2732561^2 + 3707320^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211111201121 is a prime.

It is a super-2 number, since 2×21211111201121² (a number of 27 digits) contains 22 as substring.

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 21211111201121.

It is not an unprimeable number, because it can be changed into a prime (21211111201171) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 8494721 + ... + 10704321.

It is an arithmetic number, because the mean of its divisors is an integer number (2675745161925).

Almost surely, 2^{21211111201121} is an apocalyptic number.

It is an amenable number.

21211111201121 is a deficient number, since it is larger than the sum of its proper divisors (194850094279).

21211111201121 is a wasteful number, since it uses less digits than its factorization.

21211111201121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2297779.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 21211111201121 its reverse (12110211111212), we get a palindrome (33321322312333).

The spelling of 21211111201121 in words is "twenty-one trillion, two hundred eleven billion, one hundred eleven million, two hundred one thousand, one hundred twenty-one".