21112100121121 has 2 divisors, whose sum is σ = 21112100121122. Its totient is φ = 21112100121120.

The previous prime is 21112100121109. The next prime is 21112100121197. The reversal of 21112100121121 is 12112100121112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15772137102225 + 5339963018896 = 3971415^2 + 2310836^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112100121121 - 2⁴¹ = 18913076865569 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112100121095 and 21112100121104.

It is not a weakly prime, because it can be changed into another prime (21112100121821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556050060560 + 10556050060561.

It is an arithmetic number, because the mean of its divisors is an integer number (10556050060561).

Almost surely, 2^{21112100121121} is an apocalyptic number.

It is an amenable number.

21112100121121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112100121121 is an equidigital number, since it uses as much as digits as its factorization.

21112100121121 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21112100121121 its reverse (12112100121112), we get a palindrome (33224200242233).

Subtracting from 21112100121121 its reverse (12112100121112), we obtain a palindrome (9000000000009).

The spelling of 21112100121121 in words is "twenty-one trillion, one hundred twelve billion, one hundred million, one hundred twenty-one thousand, one hundred twenty-one".