51715729 has 8 divisors (see below), whose sum is σ = 57614760. Its totient is φ = 46091136.

The previous prime is 51715709. The next prime is 51715747. The reversal of 51715729 is 92751715.

It can be written as a sum of positive squares in 4 ways, for example, as 3441025 + 48274704 = 1855^2 + 6948^2 .

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

It is not a de Polignac number, because 51715729 - 2¹¹ = 51713681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51715709) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68212 + ... + 68965.

It is an arithmetic number, because the mean of its divisors is an integer number (7201845).

Almost surely, 2^51715729 is an apocalyptic number.

It is an amenable number.

51715729 is a deficient number, since it is larger than the sum of its proper divisors (5899031).

51715729 is a wasteful number, since it uses less digits than its factorization.

51715729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137219.

The product of its digits is 22050, while the sum is 37.

The square root of 51715729 is about 7191.3648913124. The cubic root of 51715729 is about 372.5697156424.

The spelling of 51715729 in words is "fifty-one million, seven hundred fifteen thousand, seven hundred twenty-nine".