51687343431813 has 4 divisors (see below), whose sum is σ = 68916457909088. Its totient is φ = 34458228954540.

The previous prime is 51687343431799. The next prime is 51687343431851. The reversal of 51687343431813 is 31813434378615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51687343431813 - 2²⁹ = 51686806560901 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51687343441813) 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, 8614557238633 + ... + 8614557238638.

It is an arithmetic number, because the mean of its divisors is an integer number (17229114477272).

Almost surely, 2^{51687343431813} is an apocalyptic number.

It is an amenable number.

51687343431813 is a deficient number, since it is larger than the sum of its proper divisors (17229114477275).

51687343431813 is a wasteful number, since it uses less digits than its factorization.

51687343431813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17229114477274.

The product of its digits is 17418240, while the sum is 57.

The spelling of 51687343431813 in words is "fifty-one trillion, six hundred eighty-seven billion, three hundred forty-three million, four hundred thirty-one thousand, eight hundred thirteen".