20871845231 has 2 divisors, whose sum is σ = 20871845232. Its totient is φ = 20871845230.

The previous prime is 20871845219. The next prime is 20871845237. The reversal of 20871845231 is 13254817802.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20871845231 is a prime.

It is a super-2 number, since 2×20871845231² (a number of 21 digits) contains 22 as substring.

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 (20871845237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435922615 + 10435922616.

It is an arithmetic number, because the mean of its divisors is an integer number (10435922616).

Almost surely, 2^20871845231 is an apocalyptic number.

20871845231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20871845231 is an equidigital number, since it uses as much as digits as its factorization.

20871845231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 107520, while the sum is 41.

The spelling of 20871845231 in words is "twenty billion, eight hundred seventy-one million, eight hundred forty-five thousand, two hundred thirty-one".