51697 has 4 divisors (see below), whose sum is σ = 54756. Its totient is φ = 48640.

The previous prime is 51691. The next prime is 51713. The reversal of 51697 is 79615.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79615 = 5 ⋅15923.

It can be written as a sum of positive squares in 2 ways, for example, as 46656 + 5041 = 216^2 + 71^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1504 + ... + 1537.

It is an arithmetic number, because the mean of its divisors is an integer number (13689).

2⁵¹⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

51697 is a deficient number, since it is larger than the sum of its proper divisors (3059).

51697 is a wasteful number, since it uses less digits than its factorization.

51697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3058.

The product of its digits is 1890, while the sum is 28.

The square root of 51697 is about 227.3697429299. The cubic root of 51697 is about 37.2524734481.

The spelling of 51697 in words is "fifty-one thousand, six hundred ninety-seven".