51684812117 has 4 divisors (see below), whose sum is σ = 51685268076. Its totient is φ = 51684356160.

The previous prime is 51684812107. The next prime is 51684812147. The reversal of 51684812117 is 71121848615.

It is a happy number.

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: 71121848615 = 5 ⋅14224369723.

It can be written as a sum of positive squares in 2 ways, for example, as 49978626481 + 1706185636 = 223559^2 + 41306^2 .

It is a cyclic number.

It is not a de Polignac number, because 51684812117 - 2²⁰ = 51683763541 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 (51684812107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88463 + ... + 333459.

It is an arithmetic number, because the mean of its divisors is an integer number (12921317019).

Almost surely, 2^51684812117 is an apocalyptic number.

It is an amenable number.

51684812117 is a deficient number, since it is larger than the sum of its proper divisors (455959).

51684812117 is a wasteful number, since it uses less digits than its factorization.

51684812117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455958.

The product of its digits is 107520, while the sum is 44.

The spelling of 51684812117 in words is "fifty-one billion, six hundred eighty-four million, eight hundred twelve thousand, one hundred seventeen".