20804173 has 4 divisors (see below), whose sum is σ = 22404508. Its totient is φ = 19203840.

The previous prime is 20804159. The next prime is 20804257. The reversal of 20804173 is 37140802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37140802 = 2 ⋅18570401.

It can be written as a sum of positive squares in 2 ways, for example, as 850084 + 19954089 = 922^2 + 4467^2 .

It is a cyclic number.

It is not a de Polignac number, because 20804173 - 2¹⁷ = 20673101 is a prime.

It is a super-2 number, since 2×20804173² = 865627228427858, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20804123) 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, 800148 + ... + 800173.

It is an arithmetic number, because the mean of its divisors is an integer number (5601127).

Almost surely, 2^20804173 is an apocalyptic number.

It is an amenable number.

20804173 is a deficient number, since it is larger than the sum of its proper divisors (1600335).

20804173 is a wasteful number, since it uses less digits than its factorization.

20804173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1600334.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20804173 is about 4561.1591728419. The cubic root of 20804173 is about 275.0321637311.

Adding to 20804173 its reverse (37140802), we get a palindrome (57944975).

The spelling of 20804173 in words is "twenty million, eight hundred four thousand, one hundred seventy-three".