51685563 has 4 divisors (see below), whose sum is σ = 68914088. Its totient is φ = 34457040.

The previous prime is 51685561. The next prime is 51685591. The reversal of 51685563 is 36558615.

51685563 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 is not a de Polignac number, because 51685563 - 2¹ = 51685561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51685561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8614258 + ... + 8614263.

It is an arithmetic number, because the mean of its divisors is an integer number (17228522).

Almost surely, 2^51685563 is an apocalyptic number.

51685563 is a deficient number, since it is larger than the sum of its proper divisors (17228525).

51685563 is a wasteful number, since it uses less digits than its factorization.

51685563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17228524.

The product of its digits is 108000, while the sum is 39.

The square root of 51685563 is about 7189.2672088329. The cubic root of 51685563 is about 372.4972610642.

It can be divided in two parts, 5168 and 5563, that added together give a triangular number (10731 = T₁₄₆).

The spelling of 51685563 in words is "fifty-one million, six hundred eighty-five thousand, five hundred sixty-three".