71781786122055 has 16 divisors (see below), whose sum is σ = 114852170517504. Its totient is φ = 38283181691040.

The previous prime is 71781786121987. The next prime is 71781786122063. The reversal of 71781786122055 is 55022168718717.

It is a de Polignac number, because none of the positive numbers 2^k-71781786122055 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71781786122055.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25990099 + ... + 28619028.

It is an arithmetic number, because the mean of its divisors is an integer number (7178260657344).

Almost surely, 2^{71781786122055} is an apocalyptic number.

71781786122055 is a deficient number, since it is larger than the sum of its proper divisors (43070384395449).

71781786122055 is a wasteful number, since it uses less digits than its factorization.

71781786122055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54696766.

The product of its (nonzero) digits is 13171200, while the sum is 60.

The spelling of 71781786122055 in words is "seventy-one trillion, seven hundred eighty-one billion, seven hundred eighty-six million, one hundred twenty-two thousand, fifty-five".