71121263513 has 4 divisors (see below), whose sum is σ = 71175931428. Its totient is φ = 71066595600.

The previous prime is 71121263509. The next prime is 71121263557. The reversal of 71121263513 is 31536212117.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31536212117 = 17 ⋅1855071301.

It can be written as a sum of positive squares in 2 ways, for example, as 1471719769 + 69649543744 = 38363^2 + 263912^2 .

It is a cyclic number.

It is not a de Polignac number, because 71121263513 - 2² = 71121263509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71121263513.

It is not an unprimeable number, because it can be changed into a prime (71121263593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27332006 + ... + 27334607.

It is an arithmetic number, because the mean of its divisors is an integer number (17793982857).

Almost surely, 2^71121263513 is an apocalyptic number.

It is an amenable number.

71121263513 is a deficient number, since it is larger than the sum of its proper divisors (54667915).

71121263513 is a wasteful number, since it uses less digits than its factorization.

71121263513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54667914.

The product of its digits is 7560, while the sum is 32.

The spelling of 71121263513 in words is "seventy-one billion, one hundred twenty-one million, two hundred sixty-three thousand, five hundred thirteen".