51516560509 has 4 divisors (see below), whose sum is σ = 53292993660. Its totient is φ = 49740127360.

The previous prime is 51516560507. The next prime is 51516560527. The reversal of 51516560509 is 90506561515.

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 10955808900 + 40560751609 = 104670^2 + 201397^2 .

It is a cyclic number.

It is not a de Polignac number, because 51516560509 - 2¹ = 51516560507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51516560503) 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, 888216532 + ... + 888216589.

It is an arithmetic number, because the mean of its divisors is an integer number (13323248415).

Almost surely, 2^51516560509 is an apocalyptic number.

It is an amenable number.

51516560509 is a deficient number, since it is larger than the sum of its proper divisors (1776433151).

51516560509 is a wasteful number, since it uses less digits than its factorization.

51516560509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1776433150.

The product of its (nonzero) digits is 202500, while the sum is 43.

The spelling of 51516560509 in words is "fifty-one billion, five hundred sixteen million, five hundred sixty thousand, five hundred nine".