20861109 has 12 divisors (see below), whose sum is σ = 31105152. Its totient is φ = 13458600.

The previous prime is 20861101. The next prime is 20861119. The reversal of 20861109 is 90116802.

It is not a de Polignac number, because 20861109 - 2³ = 20861101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20861101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37107 + ... + 37664.

It is an arithmetic number, because the mean of its divisors is an integer number (2592096).

Almost surely, 2^20861109 is an apocalyptic number.

It is an amenable number.

20861109 is a deficient number, since it is larger than the sum of its proper divisors (10244043).

20861109 is a wasteful number, since it uses less digits than its factorization.

20861109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74808 (or 74805 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 20861109 is about 4567.3963042416. The cubic root of 20861109 is about 275.2828340778.

The spelling of 20861109 in words is "twenty million, eight hundred sixty-one thousand, one hundred nine".