20660005 has 4 divisors (see below), whose sum is σ = 24792012. Its totient is φ = 16528000.

The previous prime is 20659999. The next prime is 20660047. The reversal of 20660005 is 50006602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50006602 = 2 ⋅25003301.

It can be written as a sum of positive squares in 2 ways, for example, as 4322241 + 16337764 = 2079^2 + 4042^2 .

It is not a de Polignac number, because 20660005 - 2³ = 20659997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2065996 + ... + 2066005.

It is an arithmetic number, because the mean of its divisors is an integer number (6198003).

Almost surely, 2^20660005 is an apocalyptic number.

It is an amenable number.

20660005 is a deficient number, since it is larger than the sum of its proper divisors (4132007).

20660005 is an equidigital number, since it uses as much as digits as its factorization.

20660005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4132006.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 20660005 is about 4545.3278209608. The cubic root of 20660005 is about 274.3953879340.

Adding to 20660005 its reverse (50006602), we get a palindrome (70666607).

The spelling of 20660005 in words is "twenty million, six hundred sixty thousand, five".