20802185 has 4 divisors (see below), whose sum is σ = 24962628. Its totient is φ = 16641744.

The previous prime is 20802167. The next prime is 20802233. The reversal of 20802185 is 58120802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58120802 = 2 ⋅29060401.

It can be written as a sum of positive squares in 2 ways, for example, as 16192576 + 4609609 = 4024^2 + 2147^2 .

It is a cyclic number.

It is not a de Polignac number, because 20802185 - 2⁸ = 20801929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2080214 + ... + 2080223.

It is an arithmetic number, because the mean of its divisors is an integer number (6240657).

Almost surely, 2^20802185 is an apocalyptic number.

It is an amenable number.

20802185 is a deficient number, since it is larger than the sum of its proper divisors (4160443).

20802185 is an equidigital number, since it uses as much as digits as its factorization.

20802185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4160442.

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 20802185 is about 4560.9412405774. The cubic root of 20802185 is about 275.0234029670.

Adding to 20802185 its reverse (58120802), we get a palindrome (78922987).

The spelling of 20802185 in words is "twenty million, eight hundred two thousand, one hundred eighty-five".