51481271813 has 8 divisors (see below), whose sum is σ = 51932225496. Its totient is φ = 51032217600.

The previous prime is 51481271731. The next prime is 51481271827. The reversal of 51481271813 is 31817218415.

It can be written as a sum of positive squares in 4 ways, for example, as 8573463649 + 42907808164 = 92593^2 + 207142^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51481271813 - 2⁸ = 51481271557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51481271833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 420398 + ... + 528863.

It is an arithmetic number, because the mean of its divisors is an integer number (6491528187).

Almost surely, 2^51481271813 is an apocalyptic number.

It is an amenable number.

51481271813 is a deficient number, since it is larger than the sum of its proper divisors (450953683).

51481271813 is a wasteful number, since it uses less digits than its factorization.

51481271813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 949735.

The product of its digits is 53760, while the sum is 41.

The spelling of 51481271813 in words is "fifty-one billion, four hundred eighty-one million, two hundred seventy-one thousand, eight hundred thirteen".