871442787121 has 9 divisors (see below), whose sum is σ = 884707021611. Its totient is φ = 858374566632.

The previous prime is 871442787109. The next prime is 871442787139. The reversal of 871442787121 is 121787244178.

The square root of 871442787121 is 933511.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 869192613025 + 2250174096 = 932305^2 + 47436^2 .

It is not a de Polignac number, because 871442787121 - 2³³ = 862852852529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (871442787101) 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 in 8 ways as a sum of consecutive naturals, for example, 62538271 + ... + 62552203.

It is an arithmetic number, because the mean of its divisors is an integer number (98300780179).

Almost surely, 2^871442787121 is an apocalyptic number.

871442787121 is the 933511-st square number.

871442787121 is the 466756-th centered octagonal number.

It is an amenable number.

871442787121 is a deficient number, since it is larger than the sum of its proper divisors (13264234490).

871442787121 is an frugal number, since it uses more digits than its factorization.

871442787121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28000 (or 14000 counting only the distinct ones).

The product of its digits is 1404928, while the sum is 52.

The spelling of 871442787121 in words is "eight hundred seventy-one billion, four hundred forty-two million, seven hundred eighty-seven thousand, one hundred twenty-one".