21121112101121 has 2 divisors, whose sum is σ = 21121112101122. Its totient is φ = 21121112101120.

The previous prime is 21121112101087. The next prime is 21121112101123. The reversal of 21121112101121 is 12110121112112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18633993857521 + 2487118243600 = 4316711^2 + 1577060^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121112101121 is a prime.

It is a super-2 number, since 2×21121112101121² (a number of 27 digits) contains 22 as substring.

Together with 21121112101123, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21121112101121.

It is not a weakly prime, because it can be changed into another prime (21121112101123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560556050560 + 10560556050561.

It is an arithmetic number, because the mean of its divisors is an integer number (10560556050561).

Almost surely, 2^{21121112101121} is an apocalyptic number.

It is an amenable number.

21121112101121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121112101121 is an equidigital number, since it uses as much as digits as its factorization.

21121112101121 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 17.

Adding to 21121112101121 its reverse (12110121112112), we get a palindrome (33231233213233).

The spelling of 21121112101121 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twelve million, one hundred one thousand, one hundred twenty-one".