21112110109 has 2 divisors, whose sum is σ = 21112110110. Its totient is φ = 21112110108.

The previous prime is 21112110037. The next prime is 21112110119. The reversal of 21112110109 is 90101121112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18130622500 + 2981487609 = 134650^2 + 54603^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112110109 - 2¹³ = 21112101917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112110119) 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, 10556055054 + 10556055055.

It is an arithmetic number, because the mean of its divisors is an integer number (10556055055).

Almost surely, 2^21112110109 is an apocalyptic number.

It is an amenable number.

21112110109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112110109 is an equidigital number, since it uses as much as digits as its factorization.

21112110109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 19.

The spelling of 21112110109 in words is "twenty-one billion, one hundred twelve million, one hundred ten thousand, one hundred nine".