20507305 has 24 divisors (see below), whose sum is σ = 30462912. Its totient is φ = 12976704.

The previous prime is 20507281. The next prime is 20507323. The reversal of 20507305 is 50370502.

It is not a de Polignac number, because 20507305 - 2⁵ = 20507273 is a prime.

It is a Duffinian 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 23 ways as a sum of consecutive naturals, for example, 4182 + ... + 7648.

It is an arithmetic number, because the mean of its divisors is an integer number (1269288).

Almost surely, 2^20507305 is an apocalyptic number.

It is an amenable number.

20507305 is a deficient number, since it is larger than the sum of its proper divisors (9955607).

20507305 is a wasteful number, since it uses less digits than its factorization.

20507305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3505 (or 3492 counting only the distinct ones).

The product of its (nonzero) digits is 1050, while the sum is 22.

The square root of 20507305 is about 4528.4991995141. The cubic root of 20507305 is about 273.7176883389.

Adding to 20507305 its reverse (50370502), we get a palindrome (70877807).

The spelling of 20507305 in words is "twenty million, five hundred seven thousand, three hundred five".