71871385172 has 6 divisors (see below), whose sum is σ = 125774924058. Its totient is φ = 35935692584.

The previous prime is 71871385171. The next prime is 71871385193. The reversal of 71871385172 is 27158317817.

It can be written as a sum of positive squares in only one way, i.e., 62883586756 + 8987798416 = 250766^2 + 94804^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 71871385172.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71871385171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8983923143 + ... + 8983923150.

It is an arithmetic number, because the mean of its divisors is an integer number (20962487343).

Almost surely, 2^71871385172 is an apocalyptic number.

It is an amenable number.

71871385172 is a deficient number, since it is larger than the sum of its proper divisors (53903538886).

71871385172 is a wasteful number, since it uses less digits than its factorization.

71871385172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17967846297 (or 17967846295 counting only the distinct ones).

The product of its digits is 658560, while the sum is 50.

The spelling of 71871385172 in words is "seventy-one billion, eight hundred seventy-one million, three hundred eighty-five thousand, one hundred seventy-two".