20817113 has 4 divisors (see below), whose sum is σ = 20869428. Its totient is φ = 20764800.

The previous prime is 20817109. The next prime is 20817127. The reversal of 20817113 is 31171802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16540489 + 4276624 = 4067^2 + 2068^2 .

It is a cyclic number.

It is not a de Polignac number, because 20817113 - 2² = 20817109 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20817133) 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, 25556 + ... + 26357.

It is an arithmetic number, because the mean of its divisors is an integer number (5217357).

Almost surely, 2^20817113 is an apocalyptic number.

It is an amenable number.

20817113 is a deficient number, since it is larger than the sum of its proper divisors (52315).

20817113 is an equidigital number, since it uses as much as digits as its factorization.

20817113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52314.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 20817113 is about 4562.5774513974. The cubic root of 20817113 is about 275.0891743860.

Adding to 20817113 its reverse (31171802), we get a palindrome (51988915).

The spelling of 20817113 in words is "twenty million, eight hundred seventeen thousand, one hundred thirteen".