71005866881 has 4 divisors (see below), whose sum is σ = 71803685700. Its totient is φ = 70208048064.

The previous prime is 71005866821. The next prime is 71005866937. The reversal of 71005866881 is 18866850017.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11281838656 + 59724028225 = 106216^2 + 244385^2 .

It is a cyclic number.

It is not a de Polignac number, because 71005866881 - 2⁶ = 71005866817 is a prime.

It is a super-2 number, since 2×71005866881² (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 (71005866821) 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, 398909276 + ... + 398909453.

It is an arithmetic number, because the mean of its divisors is an integer number (17950921425).

Almost surely, 2^71005866881 is an apocalyptic number.

It is an amenable number.

71005866881 is a deficient number, since it is larger than the sum of its proper divisors (797818819).

71005866881 is an equidigital number, since it uses as much as digits as its factorization.

71005866881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797818818.

The product of its (nonzero) digits is 645120, while the sum is 50.

The spelling of 71005866881 in words is "seventy-one billion, five million, eight hundred sixty-six thousand, eight hundred eighty-one".