20730505 has 8 divisors (see below), whose sum is σ = 25734600. Its totient is φ = 16012416.

The previous prime is 20730491. The next prime is 20730529. The reversal of 20730505 is 50503702.

It can be written as a sum of positive squares in 4 ways, for example, as 9801 + 20720704 = 99^2 + 4552^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20730505 - 2⁹ = 20729993 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 71340 + ... + 71629.

It is an arithmetic number, because the mean of its divisors is an integer number (3216825).

Almost surely, 2^20730505 is an apocalyptic number.

It is an amenable number.

20730505 is a deficient number, since it is larger than the sum of its proper divisors (5004095).

20730505 is a wasteful number, since it uses less digits than its factorization.

20730505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143003.

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

The square root of 20730505 is about 4553.0764324795. The cubic root of 20730505 is about 274.7071483036.

The spelling of 20730505 in words is "twenty million, seven hundred thirty thousand, five hundred five".