51008689 has 4 divisors (see below), whose sum is σ = 51085156. Its totient is φ = 50932224.

The previous prime is 51008669. The next prime is 51008693. The reversal of 51008689 is 98680015.

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 29246464 + 21762225 = 5408^2 + 4665^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51008689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51008669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37224 + ... + 38569.

It is an arithmetic number, because the mean of its divisors is an integer number (12771289).

Almost surely, 2^51008689 is an apocalyptic number.

It is an amenable number.

51008689 is a deficient number, since it is larger than the sum of its proper divisors (76467).

51008689 is an equidigital number, since it uses as much as digits as its factorization.

51008689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76466.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 51008689 is about 7142.0367543160. The cubic root of 51008689 is about 370.8640362184.

The spelling of 51008689 in words is "fifty-one million, eight thousand, six hundred eighty-nine".