20813806 has 16 divisors (see below), whose sum is σ = 34406064. Its totient is φ = 9382464.

The previous prime is 20813791. The next prime is 20813813. The reversal of 20813806 is 60831802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8191 + ... + 10426.

It is an arithmetic number, because the mean of its divisors is an integer number (2150379).

Almost surely, 2^20813806 is an apocalyptic number.

20813806 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20813806 is a deficient number, since it is larger than the sum of its proper divisors (13592258).

20813806 is a wasteful number, since it uses less digits than its factorization.

20813806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18675.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 20813806 is about 4562.2150321965. The cubic root of 20813806 is about 275.0746067548.

The spelling of 20813806 in words is "twenty million, eight hundred thirteen thousand, eight hundred six".