20813836 has 12 divisors (see below), whose sum is σ = 36470728. Its totient is φ = 10393632.

The previous prime is 20813813. The next prime is 20813839. The reversal of 20813836 is 63831802.

It is a junction number, because it is equal to n+sod(n) for n = 20813798 and 20813807.

It is not an unprimeable number, because it can be changed into a prime (20813839) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 760 + ... + 6496.

Almost surely, 2^20813836 is an apocalyptic number.

It is an amenable number.

20813836 is a deficient number, since it is larger than the sum of its proper divisors (15656892).

20813836 is a wasteful number, since it uses less digits than its factorization.

20813836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6648 (or 6646 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 20813836 is about 4562.2183200719. The cubic root of 20813836 is about 275.0747389144.

The spelling of 20813836 in words is "twenty million, eight hundred thirteen thousand, eight hundred thirty-six".