21130122109 has 2 divisors, whose sum is σ = 21130122110. Its totient is φ = 21130122108.

The previous prime is 21130122043. The next prime is 21130122157. The reversal of 21130122109 is 90122103112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18475605625 + 2654516484 = 135925^2 + 51522^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130122109 - 2²⁵ = 21096567677 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21130122109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21130222109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565061054 + 10565061055.

It is an arithmetic number, because the mean of its divisors is an integer number (10565061055).

Almost surely, 2^21130122109 is an apocalyptic number.

It is an amenable number.

21130122109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130122109 is an equidigital number, since it uses as much as digits as its factorization.

21130122109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 21130122109 in words is "twenty-one billion, one hundred thirty million, one hundred twenty-two thousand, one hundred nine".