51647 has 2 divisors, whose sum is σ = 51648. Its totient is φ = 51646.

The previous prime is 51637. The next prime is 51659. The reversal of 51647 is 74615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51647 - 2⁴ = 51631 is a prime.

It is a plaindrome in base 8.

It is a nialpdrome in base 9.

It is a zygodrome in base 9.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51607) 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 as a sum of consecutive naturals, namely, 25823 + 25824.

It is an arithmetic number, because the mean of its divisors is an integer number (25824).

2⁵¹⁶⁴⁷ is an apocalyptic number.

51647 is a deficient number, since it is larger than the sum of its proper divisors (1).

51647 is an equidigital number, since it uses as much as digits as its factorization.

51647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 51647 is about 227.2597632666. The cubic root of 51647 is about 37.2404596981.

The spelling of 51647 in words is "fifty-one thousand, six hundred forty-seven".