51709709 has 8 divisors (see below), whose sum is σ = 52492440. Its totient is φ = 50932800.

The previous prime is 51709703. The next prime is 51709711. The reversal of 51709709 is 90790715.

It can be written as a sum of positive squares in 4 ways, for example, as 5428900 + 46280809 = 2330^2 + 6803^2 .

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 51709709 - 2²⁰ = 50661133 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 (51709703) 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, 18419 + ... + 21039.

It is an arithmetic number, because the mean of its divisors is an integer number (6561555).

Almost surely, 2^51709709 is an apocalyptic number.

It is an amenable number.

51709709 is a deficient number, since it is larger than the sum of its proper divisors (782731).

51709709 is a wasteful number, since it uses less digits than its factorization.

51709709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2911.

The product of its (nonzero) digits is 19845, while the sum is 38.

The square root of 51709709 is about 7190.9463215908. The cubic root of 51709709 is about 372.5552586821. Note that the first 3 decimals are identical.

The spelling of 51709709 in words is "fifty-one million, seven hundred nine thousand, seven hundred nine".