51043615521 has 4 divisors (see below), whose sum is σ = 68058154032. Its totient is φ = 34029077012.

The previous prime is 51043615499. The next prime is 51043615607. The reversal of 51043615521 is 12551634015.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51043615521 - 2¹¹ = 51043613473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51043615621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8507269251 + ... + 8507269256.

It is an arithmetic number, because the mean of its divisors is an integer number (17014538508).

Almost surely, 2^51043615521 is an apocalyptic number.

It is an amenable number.

51043615521 is a deficient number, since it is larger than the sum of its proper divisors (17014538511).

51043615521 is a wasteful number, since it uses less digits than its factorization.

51043615521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17014538510.

The product of its (nonzero) digits is 18000, while the sum is 33.

The spelling of 51043615521 in words is "fifty-one billion, forty-three million, six hundred fifteen thousand, five hundred twenty-one".