20730005 has 4 divisors (see below), whose sum is σ = 24876012. Its totient is φ = 16584000.

The previous prime is 20729993. The next prime is 20730011. The reversal of 20730005 is 50003702.

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 7524049 + 13205956 = 2743^2 + 3634^2 .

It is not a de Polignac number, because 20730005 - 2²⁰ = 19681429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2072996 + ... + 2073005.

It is an arithmetic number, because the mean of its divisors is an integer number (6219003).

Almost surely, 2^20730005 is an apocalyptic number.

It is an amenable number.

20730005 is a deficient number, since it is larger than the sum of its proper divisors (4146007).

20730005 is an equidigital number, since it uses as much as digits as its factorization.

20730005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4146006.

The product of its (nonzero) digits is 210, while the sum is 17.

The square root of 20730005 is about 4553.0215242188. The cubic root of 20730005 is about 274.7049397277.

Adding to 20730005 its reverse (50003702), we get a palindrome (70733707).

The spelling of 20730005 in words is "twenty million, seven hundred thirty thousand, five".