20871813117 has 16 divisors (see below), whose sum is σ = 28058537600. Its totient is φ = 13800264192.

The previous prime is 20871813049. The next prime is 20871813119. The reversal of 20871813117 is 71131817802.

It is not a de Polignac number, because 20871813117 - 2⁸ = 20871812861 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 (20871813119) 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, 131013 + ... + 242709.

It is an arithmetic number, because the mean of its divisors is an integer number (1753658600).

Almost surely, 2^20871813117 is an apocalyptic number.

It is an amenable number.

20871813117 is a deficient number, since it is larger than the sum of its proper divisors (7186724483).

20871813117 is a wasteful number, since it uses less digits than its factorization.

20871813117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112212.

The product of its (nonzero) digits is 18816, while the sum is 39.

The spelling of 20871813117 in words is "twenty billion, eight hundred seventy-one million, eight hundred thirteen thousand, one hundred seventeen".