20425205 has 4 divisors (see below), whose sum is σ = 24510252. Its totient is φ = 16340160.

The previous prime is 20425189. The next prime is 20425217. The reversal of 20425205 is 50252402.

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 7623121 + 12802084 = 2761^2 + 3578^2 .

It is not a de Polignac number, because 20425205 - 2⁴ = 20425189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2042516 + ... + 2042525.

It is an arithmetic number, because the mean of its divisors is an integer number (6127563).

Almost surely, 2^20425205 is an apocalyptic number.

It is an amenable number.

20425205 is a deficient number, since it is larger than the sum of its proper divisors (4085047).

20425205 is an equidigital number, since it uses as much as digits as its factorization.

20425205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4085046.

The product of its (nonzero) digits is 800, while the sum is 20.

The square root of 20425205 is about 4519.4252953224. The cubic root of 20425205 is about 273.3519279768.

Adding to 20425205 its reverse (50252402), we get a palindrome (70677607).

The spelling of 20425205 in words is "twenty million, four hundred twenty-five thousand, two hundred five".