51864 has 16 divisors (see below), whose sum is σ = 129720. Its totient is φ = 17280.

The previous prime is 51859. The next prime is 51869. The reversal of 51864 is 46815.

It is an interprime number because it is at equal distance from previous prime (51859) and next prime (51869).

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 2161 = 51864 / (5 + 1 + 8 + 6 + 4).

It is a nialpdrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 51864.

It is not an unprimeable number, because it can be changed into a prime (51869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1057 + ... + 1104.

2⁵¹⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

51864 is an abundant number, since it is smaller than the sum of its proper divisors (77856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64860).

51864 is a wasteful number, since it uses less digits than its factorization.

51864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2170 (or 2166 counting only the distinct ones).

The product of its digits is 960, while the sum is 24.

The square root of 51864 is about 227.7366900611. The cubic root of 51864 is about 37.2925433180.

The spelling of 51864 in words is "fifty-one thousand, eight hundred sixty-four".