21100120111123 has 2 divisors, whose sum is σ = 21100120111124. Its totient is φ = 21100120111122.

The previous prime is 21100120111093. The next prime is 21100120111163. The reversal of 21100120111123 is 32111102100112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21100120111123 is a prime.

It is a super-2 number, since 2×21100120111123² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21100120111097 and 21100120111106.

It is not a weakly prime, because it can be changed into another prime (21100120111163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550060055561 + 10550060055562.

It is an arithmetic number, because the mean of its divisors is an integer number (10550060055562).

Almost surely, 2^{21100120111123} is an apocalyptic number.

21100120111123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100120111123 is an equidigital number, since it uses as much as digits as its factorization.

21100120111123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21100120111123 its reverse (32111102100112), we get a palindrome (53211222211235).

The spelling of 21100120111123 in words is "twenty-one trillion, one hundred billion, one hundred twenty million, one hundred eleven thousand, one hundred twenty-three".