18078840 has 96 divisors (see below), whose sum is σ = 63292320. Its totient is φ = 4449024.

The previous prime is 18078779. The next prime is 18078857. The reversal of 18078840 is 4887081.

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 = 18078795 and 18078804.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 2749 + ... + 6611.

It is an arithmetic number, because the mean of its divisors is an integer number (659295).

Almost surely, 2^18078840 is an apocalyptic number.

18078840 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 18078840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31646160).

18078840 is an abundant number, since it is smaller than the sum of its proper divisors (45213480).

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

18078840 is a wasteful number, since it uses less digits than its factorization.

18078840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3893 (or 3886 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 18078840 is about 4251.9219183800. The cubic root of 18078840 is about 262.4562103826.

The spelling of 18078840 in words is "eighteen million, seventy-eight thousand, eight hundred forty".