20408109 has 16 divisors (see below), whose sum is σ = 30329280. Its totient is φ = 12130560.

The previous prime is 20408081. The next prime is 20408117. The reversal of 20408109 is 90180402.

It is not a de Polignac number, because 20408109 - 2⁵ = 20408077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20408189) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9562 + ... + 11499.

It is an arithmetic number, because the mean of its divisors is an integer number (1895580).

Almost surely, 2^20408109 is an apocalyptic number.

It is an amenable number.

20408109 is a deficient number, since it is larger than the sum of its proper divisors (9921171).

20408109 is a wasteful number, since it uses less digits than its factorization.

20408109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21100.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 20408109 is about 4517.5335084535. The cubic root of 20408109 is about 273.2756410395.

The spelling of 20408109 in words is "twenty million, four hundred eight thousand, one hundred nine".