20149109 has 2 divisors, whose sum is σ = 20149110. Its totient is φ = 20149108.

The previous prime is 20149099. The next prime is 20149117. The reversal of 20149109 is 90194102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11710084 + 8439025 = 3422^2 + 2905^2 .

It is a cyclic number.

It is not a de Polignac number, because 20149109 - 2²⁰ = 19100533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20149159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10074554 + 10074555.

It is an arithmetic number, because the mean of its divisors is an integer number (10074555).

Almost surely, 2^20149109 is an apocalyptic number.

It is an amenable number.

20149109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20149109 is an equidigital number, since it uses as much as digits as its factorization.

20149109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 20149109 is about 4488.7758910420. The cubic root of 20149109 is about 272.1146656464.

The spelling of 20149109 in words is "twenty million, one hundred forty-nine thousand, one hundred nine".