18421344 has 144 divisors (see below), whose sum is σ = 57238272. Its totient is φ = 5816448.

The previous prime is 18421343. The next prime is 18421349. The reversal of 18421344 is 44312481.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421343) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 178797 + ... + 178899.

It is an arithmetic number, because the mean of its divisors is an integer number (397488).

Almost surely, 2^18421344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18421344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28619136).

18421344 is an abundant number, since it is smaller than the sum of its proper divisors (38816928).

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

18421344 is a wasteful number, since it uses less digits than its factorization.

18421344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 131 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 18421344 is about 4292.0093196544. The cubic root of 18421344 is about 264.1032653869.

It can be divided in two parts, 184 and 21344, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 18421344 in words is "eighteen million, four hundred twenty-one thousand, three hundred forty-four".