20304505 has 12 divisors (see below), whose sum is σ = 26384940. Its totient is φ = 14993472.

The previous prime is 20304503. The next prime is 20304523. The reversal of 20304505 is 50540302.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 135424 + 20169081 = 368^2 + 4491^2 .

It is not a de Polignac number, because 20304505 - 2¹ = 20304503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20304503) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11170 + ... + 12859.

It is an arithmetic number, because the mean of its divisors is an integer number (2198745).

Almost surely, 2^20304505 is an apocalyptic number.

It is an amenable number.

20304505 is a deficient number, since it is larger than the sum of its proper divisors (6080435).

20304505 is a wasteful number, since it uses less digits than its factorization.

20304505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24060 (or 24047 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 19.

The square root of 20304505 is about 4506.0520414216. The cubic root of 20304505 is about 272.8124183810.

Adding to 20304505 its reverse (50540302), we get a palindrome (70844807).

The spelling of 20304505 in words is "twenty million, three hundred four thousand, five hundred five".