871837563721 has 2 divisors, whose sum is σ = 871837563722. Its totient is φ = 871837563720.

The previous prime is 871837563719. The next prime is 871837563757. The reversal of 871837563721 is 127365738178.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 625900917321 + 245936646400 = 791139^2 + 495920^2 .

It is a cyclic number.

It is not a de Polignac number, because 871837563721 - 2¹ = 871837563719 is a prime.

Together with 871837563719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (871837563781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 435918781860 + 435918781861.

It is an arithmetic number, because the mean of its divisors is an integer number (435918781861).

Almost surely, 2^871837563721 is an apocalyptic number.

It is an amenable number.

871837563721 is a deficient number, since it is larger than the sum of its proper divisors (1).

871837563721 is an equidigital number, since it uses as much as digits as its factorization.

871837563721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11854080, while the sum is 58.

The spelling of 871837563721 in words is "eight hundred seventy-one billion, eight hundred thirty-seven million, five hundred sixty-three thousand, seven hundred twenty-one".