20143205 has 4 divisors (see below), whose sum is σ = 24171852. Its totient is φ = 16114560.

The previous prime is 20143171. The next prime is 20143219. The reversal of 20143205 is 50234102.

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 13184161 + 6959044 = 3631^2 + 2638^2 .

It is not a de Polignac number, because 20143205 - 2¹² = 20139109 is a prime.

It is a Duffinian number.

It is a congruent 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, 2014316 + ... + 2014325.

It is an arithmetic number, because the mean of its divisors is an integer number (6042963).

Almost surely, 2^20143205 is an apocalyptic number.

It is an amenable number.

20143205 is a deficient number, since it is larger than the sum of its proper divisors (4028647).

20143205 is an equidigital number, since it uses as much as digits as its factorization.

20143205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4028646.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20143205 is about 4488.1182025432. The cubic root of 20143205 is about 272.0880851174.

Adding to 20143205 its reverse (50234102), we get a palindrome (70377307).

The spelling of 20143205 in words is "twenty million, one hundred forty-three thousand, two hundred five".