20871271 has 4 divisors (see below), whose sum is σ = 21591000. Its totient is φ = 20151544.

The previous prime is 20871251. The next prime is 20871283. The reversal of 20871271 is 17217802.

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 20871271 - 2¹¹ = 20869223 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 (20871251) 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, 359821 + ... + 359878.

It is an arithmetic number, because the mean of its divisors is an integer number (5397750).

Almost surely, 2^20871271 is an apocalyptic number.

20871271 is a deficient number, since it is larger than the sum of its proper divisors (719729).

20871271 is an equidigital number, since it uses as much as digits as its factorization.

20871271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719728.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 20871271 is about 4568.5086187945. The cubic root of 20871271 is about 275.3275260139.

The spelling of 20871271 in words is "twenty million, eight hundred seventy-one thousand, two hundred seventy-one".