20806879 has 4 divisors (see below), whose sum is σ = 20866176. Its totient is φ = 20747584.

The previous prime is 20806871. The next prime is 20806897. The reversal of 20806879 is 97860802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20806879 - 2³ = 20806871 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20806871) 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, 29119 + ... + 29824.

It is an arithmetic number, because the mean of its divisors is an integer number (5216544).

Almost surely, 2^20806879 is an apocalyptic number.

20806879 is a deficient number, since it is larger than the sum of its proper divisors (59297).

20806879 is an equidigital number, since it uses as much as digits as its factorization.

20806879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59296.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 20806879 is about 4561.4557983170. The cubic root of 20806879 is about 275.0440876974.

The spelling of 20806879 in words is "twenty million, eight hundred six thousand, eight hundred seventy-nine".