71561778111173 has 16 divisors (see below), whose sum is σ = 82938605137920. Its totient is φ = 60473417886000.

The previous prime is 71561778111137. The next prime is 71561778111283. The reversal of 71561778111173 is 37111187716517.

It is not a de Polignac number, because 71561778111173 - 2⁴⁴ = 53969592066757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71561778116173) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21483218 + ... + 24589676.

It is an arithmetic number, because the mean of its divisors is an integer number (5183662821120).

Almost surely, 2^{71561778111173} is an apocalyptic number.

It is an amenable number.

71561778111173 is a deficient number, since it is larger than the sum of its proper divisors (11376827026747).

71561778111173 is a wasteful number, since it uses less digits than its factorization.

71561778111173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3152888.

The product of its digits is 1728720, while the sum is 56.

The spelling of 71561778111173 in words is "seventy-one trillion, five hundred sixty-one billion, seven hundred seventy-eight million, one hundred eleven thousand, one hundred seventy-three".