20305205 has 16 divisors (see below), whose sum is σ = 26766720. Its totient is φ = 14718528.

The previous prime is 20305199. The next prime is 20305211. The reversal of 20305205 is 50250302.

It is an interprime number because it is at equal distance from previous prime (20305199) and next prime (20305211).

It is not a de Polignac number, because 20305205 - 2⁴ = 20305189 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2462 + ... + 6831.

It is an arithmetic number, because the mean of its divisors is an integer number (1672920).

Almost surely, 2^20305205 is an apocalyptic number.

It is an amenable number.

20305205 is a deficient number, since it is larger than the sum of its proper divisors (6461515).

20305205 is a wasteful number, since it uses less digits than its factorization.

20305205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9340.

The product of its (nonzero) digits is 300, while the sum is 17.

The square root of 20305205 is about 4506.1297140673. The cubic root of 20305205 is about 272.8155534242.

Adding to 20305205 its reverse (50250302), we get a palindrome (70555507).

The spelling of 20305205 in words is "twenty million, three hundred five thousand, two hundred five".