20305505 has 8 divisors (see below), whose sum is σ = 26581824. Its totient is φ = 14767600.

The previous prime is 20305487. The next prime is 20305507. The reversal of 20305505 is 50550302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20305505 - 2¹⁰ = 20304481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20305507) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 184541 + ... + 184650.

It is an arithmetic number, because the mean of its divisors is an integer number (3322728).

Almost surely, 2^20305505 is an apocalyptic number.

It is an amenable number.

20305505 is a deficient number, since it is larger than the sum of its proper divisors (6276319).

20305505 is a wasteful number, since it uses less digits than its factorization.

20305505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369207.

The product of its (nonzero) digits is 750, while the sum is 20.

The square root of 20305505 is about 4506.1630019341. The cubic root of 20305505 is about 272.8168969921.

Adding to 20305505 its reverse (50550302), we get a palindrome (70855807).

The spelling of 20305505 in words is "twenty million, three hundred five thousand, five hundred five".