51684358513 has 4 divisors (see below), whose sum is σ = 51837724900. Its totient is φ = 51530992128.

The previous prime is 51684358499. The next prime is 51684358547. The reversal of 51684358513 is 31585348615.

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 31789820209 + 19894538304 = 178297^2 + 141048^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51684358513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51684358553) 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, 76682688 + ... + 76683361.

It is an arithmetic number, because the mean of its divisors is an integer number (12959431225).

Almost surely, 2^51684358513 is an apocalyptic number.

It is an amenable number.

51684358513 is a deficient number, since it is larger than the sum of its proper divisors (153366387).

51684358513 is a wasteful number, since it uses less digits than its factorization.

51684358513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153366386.

The product of its digits is 1728000, while the sum is 49.

The spelling of 51684358513 in words is "fifty-one billion, six hundred eighty-four million, three hundred fifty-eight thousand, five hundred thirteen".