21111211110121 has 32 divisors (see below), whose sum is σ = 23490641571840. Its totient is φ = 18811888233600.

The previous prime is 21111211110113. The next prime is 21111211110133. The reversal of 21111211110121 is 12101111211112.

It is not a de Polignac number, because 21111211110121 - 2³ = 21111211110113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111211110095 and 21111211110104.

It is not an unprimeable number, because it can be changed into a prime (21111211110151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115076950 + ... + 115260256.

It is an arithmetic number, because the mean of its divisors is an integer number (734082549120).

Almost surely, 2^{21111211110121} is an apocalyptic number.

It is an amenable number.

21111211110121 is a deficient number, since it is larger than the sum of its proper divisors (2379430461719).

21111211110121 is a wasteful number, since it uses less digits than its factorization.

21111211110121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184245.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 21111211110121 its reverse (12101111211112), we get a palindrome (33212322321233).

The spelling of 21111211110121 in words is "twenty-one trillion, one hundred eleven billion, two hundred eleven million, one hundred ten thousand, one hundred twenty-one".