20109109 has 2 divisors, whose sum is σ = 20109110. Its totient is φ = 20109108.

The previous prime is 20109073. The next prime is 20109119. The reversal of 20109109 is 90190102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19554084 + 555025 = 4422^2 + 745^2 .

It is a cyclic number.

It is not a de Polignac number, because 20109109 - 2⁷ = 20108981 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20109109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20109119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054554 + 10054555.

It is an arithmetic number, because the mean of its divisors is an integer number (10054555).

Almost surely, 2^20109109 is an apocalyptic number.

It is an amenable number.

20109109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20109109 is an equidigital number, since it uses as much as digits as its factorization.

20109109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 20109109 is about 4484.3181198483. The cubic root of 20109109 is about 271.9344790639.

The spelling of 20109109 in words is "twenty million, one hundred nine thousand, one hundred nine".