20566871 has 16 divisors (see below), whose sum is σ = 23200128. Its totient is φ = 18105600.

The previous prime is 20566867. The next prime is 20566877. The reversal of 20566871 is 17866502.

It is not a de Polignac number, because 20566871 - 2² = 20566867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20566877) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24641 + ... + 25461.

It is an arithmetic number, because the mean of its divisors is an integer number (1450008).

Almost surely, 2^20566871 is an apocalyptic number.

20566871 is a deficient number, since it is larger than the sum of its proper divisors (2633257).

20566871 is a wasteful number, since it uses less digits than its factorization.

20566871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 922.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 20566871 is about 4535.0712232555. The cubic root of 20566871 is about 273.9824477719.

It can be divided in two parts, 205 and 66871, that added together give a palindrome (67076).

The spelling of 20566871 in words is "twenty million, five hundred sixty-six thousand, eight hundred seventy-one".