51618 has 16 divisors (see below), whose sum is σ = 118080. Its totient is φ = 14736.

The previous prime is 51613. The next prime is 51631. The reversal of 51618 is 81615.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 51594 and 51603.

It is not an unprimeable number, because it can be changed into a prime (51613) 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 7 ways as a sum of consecutive naturals, for example, 573 + ... + 656.

It is an arithmetic number, because the mean of its divisors is an integer number (7380).

2⁵¹⁶¹⁸ is an apocalyptic number.

51618 is an abundant number, since it is smaller than the sum of its proper divisors (66462).

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 (59040).

51618 is a wasteful number, since it uses less digits than its factorization.

51618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241.

The product of its digits is 240, while the sum is 21.

The square root of 51618 is about 227.1959506681. The cubic root of 51618 is about 37.2334881701.

The spelling of 51618 in words is "fifty-one thousand, six hundred eighteen".