20018871 has 12 divisors (see below), whose sum is σ = 28978248. Its totient is φ = 13317264.

The previous prime is 20018849. The next prime is 20018881. The reversal of 20018871 is 17881002.

It is not a de Polignac number, because 20018871 - 2⁶ = 20018807 is a prime.

It is a super-2 number, since 2×20018871² = 801510392229282, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20018821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2581 + ... + 6833.

It is an arithmetic number, because the mean of its divisors is an integer number (2414854).

Almost surely, 2^20018871 is an apocalyptic number.

20018871 is a deficient number, since it is larger than the sum of its proper divisors (8959377).

20018871 is a wasteful number, since it uses less digits than its factorization.

20018871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4782 (or 4779 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20018871 is about 4474.2452994891. The cubic root of 20018871 is about 271.5271077804.

Adding to 20018871 its reverse (17881002), we get a palindrome (37899873).

The spelling of 20018871 in words is "twenty million, eighteen thousand, eight hundred seventy-one".