21110122109 has 2 divisors, whose sum is σ = 21110122110. Its totient is φ = 21110122108.

The previous prime is 21110122091. The next prime is 21110122133. The reversal of 21110122109 is 90122101112.

Together with previous prime (21110122091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20299125625 + 810996484 = 142475^2 + 28478^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110122109 - 2¹² = 21110118013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21110122909) 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, 10555061054 + 10555061055.

It is an arithmetic number, because the mean of its divisors is an integer number (10555061055).

Almost surely, 2^21110122109 is an apocalyptic number.

It is an amenable number.

21110122109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110122109 is an equidigital number, since it uses as much as digits as its factorization.

21110122109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 21110122109 in words is "twenty-one billion, one hundred ten million, one hundred twenty-two thousand, one hundred nine".