20004809 has 12 divisors (see below), whose sum is σ = 22750980. Its totient is φ = 17556000.

The previous prime is 20004773. The next prime is 20004811. The reversal of 20004809 is 90840002.

It can be written as a sum of positive squares in 2 ways, for example, as 13987600 + 6017209 = 3740^2 + 2453^2 .

It is not a de Polignac number, because 20004809 - 2¹² = 20000713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20004709) 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, 659 + ... + 6359.

It is an arithmetic number, because the mean of its divisors is an integer number (1895915).

Almost surely, 2^20004809 is an apocalyptic number.

20004809 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20004809 is a deficient number, since it is larger than the sum of its proper divisors (2746171).

20004809 is a wasteful number, since it uses less digits than its factorization.

20004809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5752 (or 5741 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 20004809 is about 4472.6735852284. The cubic root of 20004809 is about 271.4635159732.

The spelling of 20004809 in words is "twenty million, four thousand, eight hundred nine".