71183780881 has 4 divisors (see below), whose sum is σ = 71184334372. Its totient is φ = 71183227392.

The previous prime is 71183780879. The next prime is 71183780887. The reversal of 71183780881 is 18808738117.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18808738117 = 13 ⋅1446826009.

It can be written as a sum of positive squares in 2 ways, for example, as 35150250256 + 36033530625 = 187484^2 + 189825^2 .

It is a cyclic number.

It is not a de Polignac number, because 71183780881 - 2¹ = 71183780879 is a prime.

It is a super-2 number, since 2×71183780881² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71183780887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28105 + ... + 378361.

It is an arithmetic number, because the mean of its divisors is an integer number (17796083593).

Almost surely, 2^71183780881 is an apocalyptic number.

It is an amenable number.

71183780881 is a deficient number, since it is larger than the sum of its proper divisors (553491).

71183780881 is a wasteful number, since it uses less digits than its factorization.

71183780881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553490.

The product of its (nonzero) digits is 602112, while the sum is 52.

The spelling of 71183780881 in words is "seventy-one billion, one hundred eighty-three million, seven hundred eighty thousand, eight hundred eighty-one".