20504205 has 16 divisors (see below), whose sum is σ = 36452160. Its totient is φ = 10935504.

The previous prime is 20504203. The next prime is 20504221. The reversal of 20504205 is 50240502.

It is not a de Polignac number, because 20504205 - 2¹ = 20504203 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20504203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75807 + ... + 76076.

It is an arithmetic number, because the mean of its divisors is an integer number (2278260).

Almost surely, 2^20504205 is an apocalyptic number.

It is an amenable number.

20504205 is a deficient number, since it is larger than the sum of its proper divisors (15947955).

20504205 is a wasteful number, since it uses less digits than its factorization.

20504205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151897 (or 151891 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

The square root of 20504205 is about 4528.1569098255. The cubic root of 20504205 is about 273.7038954069.

Adding to 20504205 its reverse (50240502), we get a palindrome (70744707).

The spelling of 20504205 in words is "twenty million, five hundred four thousand, two hundred five".