20811171 has 8 divisors (see below), whose sum is σ = 28082880. Its totient is φ = 13706792.

The previous prime is 20811157. The next prime is 20811173. The reversal of 20811171 is 17111802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20811171 - 2¹⁸ = 20549027 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20811173) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41541 + ... + 42038.

It is an arithmetic number, because the mean of its divisors is an integer number (3510360).

Almost surely, 2^20811171 is an apocalyptic number.

20811171 is a deficient number, since it is larger than the sum of its proper divisors (7271709).

20811171 is an equidigital number, since it uses as much as digits as its factorization.

20811171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83665.

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

The square root of 20811171 is about 4561.9262378956. The cubic root of 20811171 is about 275.0629982392.

Adding to 20811171 its reverse (17111802), we get a palindrome (37922973).

The spelling of 20811171 in words is "twenty million, eight hundred eleven thousand, one hundred seventy-one".