20004005 has 12 divisors (see below), whose sum is σ = 27924300. Its totient is φ = 13716864.

The previous prime is 20004001. The next prime is 20004011. The reversal of 20004005 is 50040002.

It can be written as a sum of positive squares in 2 ways, for example, as 12397441 + 7606564 = 3521^2 + 2758^2 .

It is not a de Polignac number, because 20004005 - 2² = 20004001 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20004001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40580 + ... + 41069.

It is an arithmetic number, because the mean of its divisors is an integer number (2327025).

Almost surely, 2^20004005 is an apocalyptic number.

It is an amenable number.

20004005 is a deficient number, since it is larger than the sum of its proper divisors (7920295).

20004005 is an equidigital number, since it uses as much as digits as its factorization.

20004005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81668 (or 81661 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 11.

The square root of 20004005 is about 4472.5837051977. The cubic root of 20004005 is about 271.4598791878.

Adding to 20004005 its reverse (50040002), we get a palindrome (70044007).

The spelling of 20004005 in words is "twenty million, four thousand, five".