51138559 has 4 divisors (see below), whose sum is σ = 51170904. Its totient is φ = 51106216.

The previous prime is 51138553. The next prime is 51138569. The reversal of 51138559 is 95583115.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51138559 - 2¹¹ = 51136511 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 (51138553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13672 + ... + 17005.

It is an arithmetic number, because the mean of its divisors is an integer number (12792726).

Almost surely, 2^51138559 is an apocalyptic number.

51138559 is a deficient number, since it is larger than the sum of its proper divisors (32345).

51138559 is a wasteful number, since it uses less digits than its factorization.

51138559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32344.

The product of its digits is 27000, while the sum is 37.

The square root of 51138559 is about 7151.1229188149. The cubic root of 51138559 is about 371.1785139749.

The spelling of 51138559 in words is "fifty-one million, one hundred thirty-eight thousand, five hundred fifty-nine".