20806871 has 2 divisors, whose sum is σ = 20806872. Its totient is φ = 20806870.

The previous prime is 20806867. The next prime is 20806897. The reversal of 20806871 is 17860802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20806871 - 2² = 20806867 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20806801) by changing a digit.

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 as a sum of consecutive naturals, namely, 10403435 + 10403436.

It is an arithmetic number, because the mean of its divisors is an integer number (10403436).

Almost surely, 2^20806871 is an apocalyptic number.

20806871 is a deficient number, since it is larger than the sum of its proper divisors (1).

20806871 is an equidigital number, since it uses as much as digits as its factorization.

20806871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 20806871 is about 4561.4549214039. The cubic root of 20806871 is about 275.0440524470.

The spelling of 20806871 in words is "twenty million, eight hundred six thousand, eight hundred seventy-one".