51698 has 4 divisors (see below), whose sum is σ = 77550. Its totient is φ = 25848.

The previous prime is 51691. The next prime is 51713. The reversal of 51698 is 89615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89615 = 5 ⋅17923.

It can be written as a sum of positive squares in only one way, i.e., 51529 + 169 = 227^2 + 13^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51698.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 51698.

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

51698 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12923 + ... + 12926.

2⁵¹⁶⁹⁸ is an apocalyptic number.

51698 is a deficient number, since it is larger than the sum of its proper divisors (25852).

51698 is a wasteful number, since it uses less digits than its factorization.

51698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25851.

The product of its digits is 2160, while the sum is 29.

The square root of 51698 is about 227.3719419805. The cubic root of 51698 is about 37.2527136440.

The spelling of 51698 in words is "fifty-one thousand, six hundred ninety-eight".