20804836 has 12 divisors (see below), whose sum is σ = 39209212. Its totient is φ = 9602208.

The previous prime is 20804827. The next prime is 20804837. The reversal of 20804836 is 63840802.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2742336 + 18062500 = 1656^2 + 4250^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20804798 and 20804807.

It is not an unprimeable number, because it can be changed into a prime (20804837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199995 + ... + 200098.

Almost surely, 2^20804836 is an apocalyptic number.

20804836 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20804836 is a deficient number, since it is larger than the sum of its proper divisors (18404376).

20804836 is a wasteful number, since it uses less digits than its factorization.

20804836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400110 (or 400108 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 20804836 is about 4561.2318511560. The cubic root of 20804836 is about 275.0350853307.

The spelling of 20804836 in words is "twenty million, eight hundred four thousand, eight hundred thirty-six".