21100121110121 has 6 divisors (see below), whose sum is σ = 22414315504830. Its totient is φ = 19858937515136.

The previous prime is 21100121110093. The next prime is 21100121110147. The reversal of 21100121110121 is 12101112100112.

It can be written as a sum of positive squares in 3 ways, for example, as 13442752942096 + 7657368168025 = 3666436^2 + 2767195^2 .

It is not a de Polignac number, because 21100121110121 - 2¹⁸ = 21100120847977 is a prime.

It is a super-2 number, since 2×21100121110121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100121110096 and 21100121110105.

It is not an unprimeable number, because it can be changed into a prime (21100121190121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36505399556 + ... + 36505400133.

It is an arithmetic number, because the mean of its divisors is an integer number (3735719250805).

Almost surely, 2^{21100121110121} is an apocalyptic number.

It is an amenable number.

21100121110121 is a deficient number, since it is larger than the sum of its proper divisors (1314194394709).

21100121110121 is an equidigital number, since it uses as much as digits as its factorization.

21100121110121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73010799723 (or 73010799706 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21100121110121 its reverse (12101112100112), we get a palindrome (33201233210233).

The spelling of 21100121110121 in words is "twenty-one trillion, one hundred billion, one hundred twenty-one million, one hundred ten thousand, one hundred twenty-one".