51504343211521 has 4 divisors (see below), whose sum is σ = 51880287322692. Its totient is φ = 51128399100352.

The previous prime is 51504343211513. The next prime is 51504343211537. The reversal of 51504343211521 is 12511234340515.

51504343211521 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.

It can be written as a sum of positive squares in 2 ways, for example, as 31784349093121 + 19719994118400 = 5637761^2 + 4440720^2 .

It is a cyclic number.

It is not a de Polignac number, because 51504343211521 - 2³ = 51504343211513 is a prime.

It is a super-2 number, since 2×51504343211521² (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 (51504343211591) 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, 187972055380 + ... + 187972055653.

It is an arithmetic number, because the mean of its divisors is an integer number (12970071830673).

Almost surely, 2^{51504343211521} is an apocalyptic number.

It is an amenable number.

51504343211521 is a deficient number, since it is larger than the sum of its proper divisors (375944111171).

51504343211521 is a wasteful number, since it uses less digits than its factorization.

51504343211521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375944111170.

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 51504343211521 in words is "fifty-one trillion, five hundred four billion, three hundred forty-three million, two hundred eleven thousand, five hundred twenty-one".