20811117 has 4 divisors (see below), whose sum is σ = 27748160. Its totient is φ = 13874076.

The previous prime is 20811103. The next prime is 20811121. The reversal of 20811117 is 71111802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20811117 - 2⁴ = 20811101 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20811093 and 20811102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20811127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3468517 + ... + 3468522.

It is an arithmetic number, because the mean of its divisors is an integer number (6937040).

Almost surely, 2^20811117 is an apocalyptic number.

It is an amenable number.

20811117 is a deficient number, since it is larger than the sum of its proper divisors (6937043).

20811117 is an equidigital number, since it uses as much as digits as its factorization.

20811117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6937042.

The product of its (nonzero) digits is 112, while the sum is 21.

The square root of 20811117 is about 4561.9203193392. The cubic root of 20811117 is about 275.0627603314.

Adding to 20811117 its reverse (71111802), we get a palindrome (91922919).

It can be divided in two parts, 208 and 11117, that added together give a triangular number (11325 = T₁₅₀).

The spelling of 20811117 in words is "twenty million, eight hundred eleven thousand, one hundred seventeen".