6661818 has 64 divisors (see below), whose sum is σ = 16051200. Its totient is φ = 2041200.

The previous prime is 6661783. The next prime is 6661849. The reversal of 6661818 is 8181666.

6661818 is a modest number, since divided by 1818 gives 666 as remainder.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44043 + ... + 44193.

It is an arithmetic number, because the mean of its divisors is an integer number (250800).

Almost surely, 2^6661818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6661818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8025600).

6661818 is an abundant number, since it is smaller than the sum of its proper divisors (9389382).

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

6661818 is a wasteful number, since it uses less digits than its factorization.

6661818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 218 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 6661818 is about 2581.0497864241. The cubic root of 6661818 is about 188.1615670098.

The spelling of 6661818 in words is "six million, six hundred sixty-one thousand, eight hundred eighteen".