61818 has 8 divisors (see below), whose sum is σ = 123648. Its totient is φ = 20604.

The previous prime is 61813. The next prime is 61819. The reversal of 61818 is 81816.

It is a sphenic number, since it is the product of 3 distinct primes.

61818 is an admirable number.

It is an alternating number because its digits alternate between even and odd.

61818 is a modest number, since divided by 1818 gives 6 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61813) 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, 5146 + ... + 5157.

It is an arithmetic number, because the mean of its divisors is an integer number (15456).

2⁶¹⁸¹⁸ is an apocalyptic number.

61818 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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 (61824).

61818 is a wasteful number, since it uses less digits than its factorization.

61818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10308.

The product of its digits is 384, while the sum is 24.

The square root of 61818 is about 248.6322585667. The cubic root of 61818 is about 39.5401503834.

It can be divided in two parts, 618 and 18, that added together give a palindrome (636).

The spelling of 61818 in words is "sixty-one thousand, eight hundred eighteen".