18186840 has 144 divisors (see below), whose sum is σ = 68824080. Its totient is φ = 4152960.

The previous prime is 18186823. The next prime is 18186851. The reversal of 18186840 is 4868181.

It is a super-2 number, since 2×18186840² = 661522298371200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18186795 and 18186804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 17125 + ... + 18155.

It is an arithmetic number, because the mean of its divisors is an integer number (477945).

Almost surely, 2^18186840 is an apocalyptic number.

18186840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18186840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34412040).

18186840 is an abundant number, since it is smaller than the sum of its proper divisors (50637240).

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

18186840 is a wasteful number, since it uses less digits than its factorization.

18186840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1062 (or 1048 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 18186840 is about 4264.6031468356. The cubic root of 18186840 is about 262.9777964649.

The spelling of 18186840 in words is "eighteen million, one hundred eighty-six thousand, eight hundred forty".