51518467861841 has 4 divisors (see below), whose sum is σ = 52910858885172. Its totient is φ = 50126076838512.

The previous prime is 51518467861813. The next prime is 51518467861907. The reversal of 51518467861841 is 14816876481515.

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 39775537036225 + 11742930825616 = 6306785^2 + 3426796^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51518467861841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51518467861811) 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, 696195511610 + ... + 696195511683.

It is an arithmetic number, because the mean of its divisors is an integer number (13227714721293).

Almost surely, 2^{51518467861841} is an apocalyptic number.

It is an amenable number.

51518467861841 is a deficient number, since it is larger than the sum of its proper divisors (1392391023331).

51518467861841 is a wasteful number, since it uses less digits than its factorization.

51518467861841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1392391023330.

The product of its digits is 51609600, while the sum is 65.

The spelling of 51518467861841 in words is "fifty-one trillion, five hundred eighteen billion, four hundred sixty-seven million, eight hundred sixty-one thousand, eight hundred forty-one".