51317509 has 8 divisors (see below), whose sum is σ = 54653400. Its totient is φ = 48016896.

The previous prime is 51317507. The next prime is 51317573. The reversal of 51317509 is 90571315.

51317509 = 978² + 979² + ... + 1028².

It can be written as a sum of positive squares in 4 ways, for example, as 42185025 + 9132484 = 6495^2 + 3022^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51317509 - 2¹ = 51317507 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 (51317507) 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 7 ways as a sum of consecutive naturals, for example, 5784 + ... + 11665.

It is an arithmetic number, because the mean of its divisors is an integer number (6831675).

Almost surely, 2^51317509 is an apocalyptic number.

It is an amenable number.

51317509 is a deficient number, since it is larger than the sum of its proper divisors (3335891).

51317509 is a wasteful number, since it uses less digits than its factorization.

51317509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17639.

The product of its (nonzero) digits is 4725, while the sum is 31.

The square root of 51317509 is about 7163.6240130258. The cubic root of 51317509 is about 371.6109669614.

The spelling of 51317509 in words is "fifty-one million, three hundred seventeen thousand, five hundred nine".