51540457518817 has 4 divisors (see below), whose sum is σ = 51540471879316. Its totient is φ = 51540443158320.

The previous prime is 51540457518773. The next prime is 51540457518829. The reversal of 51540457518817 is 71881575404515.

51540457518817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 4259101210081 + 47281356308736 = 2063759^2 + 6876144^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51540457518817 is a prime.

It is a super-2 number, since 2×51540457518817² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51540457518857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3403267 + ... + 10708087.

It is an arithmetic number, because the mean of its divisors is an integer number (12885117969829).

Almost surely, 2^{51540457518817} is an apocalyptic number.

It is an amenable number.

51540457518817 is a deficient number, since it is larger than the sum of its proper divisors (14360499).

51540457518817 is an equidigital number, since it uses as much as digits as its factorization.

51540457518817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14360498.

The product of its (nonzero) digits is 31360000, while the sum is 61.

The spelling of 51540457518817 in words is "fifty-one trillion, five hundred forty billion, four hundred fifty-seven million, five hundred eighteen thousand, eight hundred seventeen".