18918144 has 288 divisors, whose sum is σ = 70640640. Its totient is φ = 4866048.

The previous prime is 18918143. The next prime is 18918157. The reversal of 18918144 is 44181981.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a nude number because it is divisible by every one of its digits.

Its product of digits (9216) is a multiple of the sum of its prime factors (72).

It is a junction number, because it is equal to n+sod(n) for n = 18918099 and 18918108.

It is not an unprimeable number, because it can be changed into a prime (18918143) 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 31 ways as a sum of consecutive naturals, for example, 822517 + ... + 822539.

It is an arithmetic number, because the mean of its divisors is an integer number (245280).

Almost surely, 2^18918144 is an apocalyptic number.

18918144 is a gapful number since it is divisible by the number (14) 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 18918144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35320320).

18918144 is an abundant number, since it is smaller than the sum of its proper divisors (51722496).

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

18918144 is a wasteful number, since it uses less digits than its factorization.

18918144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 52 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 18918144 is about 4349.4992815266. The cubic root of 18918144 is about 266.4564120451.

It can be divided in two parts, 189181 and 44, that added together give a square (189225 = 435²).

The spelling of 18918144 in words is "eighteen million, nine hundred eighteen thousand, one hundred forty-four".