20809113 has 16 divisors (see below), whose sum is σ = 30373056. Its totient is φ = 12594240.

The previous prime is 20809097. The next prime is 20809121. The reversal of 20809113 is 31190802.

It is not a de Polignac number, because 20809113 - 2⁴ = 20809097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20809163) 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 15 ways as a sum of consecutive naturals, for example, 1995 + ... + 6752.

It is an arithmetic number, because the mean of its divisors is an integer number (1898316).

Almost surely, 2^20809113 is an apocalyptic number.

It is an amenable number.

20809113 is a deficient number, since it is larger than the sum of its proper divisors (9563943).

20809113 is a wasteful number, since it uses less digits than its factorization.

20809113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8824.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 20809113 is about 4561.7006697064. The cubic root of 20809113 is about 275.0539310205.

Adding to 20809113 its reverse (31190802), we get a palindrome (51999915).

The spelling of 20809113 in words is "twenty million, eight hundred nine thousand, one hundred thirteen".