20871863 has 2 divisors, whose sum is σ = 20871864. Its totient is φ = 20871862.

The previous prime is 20871859. The next prime is 20871881. The reversal of 20871863 is 36817802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20871863 - 2² = 20871859 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20871853) 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, 10435931 + 10435932.

It is an arithmetic number, because the mean of its divisors is an integer number (10435932).

Almost surely, 2^20871863 is an apocalyptic number.

20871863 is a deficient number, since it is larger than the sum of its proper divisors (1).

20871863 is an equidigital number, since it uses as much as digits as its factorization.

20871863 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20871863 is about 4568.5734097199. The cubic root of 20871863 is about 275.3301291512.

The spelling of 20871863 in words is "twenty million, eight hundred seventy-one thousand, eight hundred sixty-three".