51541620468781 has 4 divisors (see below), whose sum is σ = 51609349274364. Its totient is φ = 51473891663200.

The previous prime is 51541620468773. The next prime is 51541620468803. The reversal of 51541620468781 is 18786402614515.

It is a happy number.

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 10976300302500 + 40565320166281 = 3313050^2 + 6369091^2 .

It is a cyclic number.

It is not a de Polignac number, because 51541620468781 - 2³ = 51541620468773 is a prime.

It is a super-2 number, since 2×51541620468781² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51541620468721) 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, 33864401650 + ... + 33864403171.

It is an arithmetic number, because the mean of its divisors is an integer number (12902337318591).

Almost surely, 2^{51541620468781} is an apocalyptic number.

It is an amenable number.

51541620468781 is a deficient number, since it is larger than the sum of its proper divisors (67728805583).

51541620468781 is an equidigital number, since it uses as much as digits as its factorization.

51541620468781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67728805582.

The product of its (nonzero) digits is 12902400, while the sum is 58.

The spelling of 51541620468781 in words is "fifty-one trillion, five hundred forty-one billion, six hundred twenty million, four hundred sixty-eight thousand, seven hundred eighty-one".