20811806 has 8 divisors (see below), whose sum is σ = 31504440. Its totient is φ = 10310328.

The previous prime is 20811799. The next prime is 20811811. The reversal of 20811806 is 60811802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47516 + ... + 47951.

It is an arithmetic number, because the mean of its divisors is an integer number (3938055).

Almost surely, 2^20811806 is an apocalyptic number.

20811806 is a deficient number, since it is larger than the sum of its proper divisors (10692634).

20811806 is a wasteful number, since it uses less digits than its factorization.

20811806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95578.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 20811806 is about 4561.9958351581. The cubic root of 20811806 is about 275.0657958268.

The spelling of 20811806 in words is "twenty million, eight hundred eleven thousand, eight hundred six".