871905372781 has 2 divisors, whose sum is σ = 871905372782. Its totient is φ = 871905372780.

The previous prime is 871905372769. The next prime is 871905372791. The reversal of 871905372781 is 187273509178.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 705416891881 + 166488480900 = 839891^2 + 408030^2 .

It is a cyclic number.

It is not a de Polignac number, because 871905372781 - 2⁹ = 871905372269 is a prime.

It is a super-2 number, since 2×871905372781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (871905372791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 435952686390 + 435952686391.

It is an arithmetic number, because the mean of its divisors is an integer number (435952686391).

Almost surely, 2^871905372781 is an apocalyptic number.

It is an amenable number.

871905372781 is a deficient number, since it is larger than the sum of its proper divisors (1).

871905372781 is an equidigital number, since it uses as much as digits as its factorization.

871905372781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5927040, while the sum is 58.

The spelling of 871905372781 in words is "eight hundred seventy-one billion, nine hundred five million, three hundred seventy-two thousand, seven hundred eighty-one".