18244380 has 144 divisors (see below), whose sum is σ = 64350720. Its totient is φ = 3780480.

The previous prime is 18244363. The next prime is 18244381. The reversal of 18244380 is 8344281.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18244381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50641 + ... + 50999.

It is an arithmetic number, because the mean of its divisors is an integer number (446880).

Almost surely, 2^18244380 is an apocalyptic number.

18244380 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 18244380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32175360).

18244380 is an abundant number, since it is smaller than the sum of its proper divisors (46106340).

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

18244380 is a wasteful number, since it uses less digits than its factorization.

18244380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 18244380 is about 4271.3440507643. The cubic root of 18244380 is about 263.2548431706.

Subtracting from 18244380 its reverse (8344281), we obtain a palindrome (9900099).

The spelling of 18244380 in words is "eighteen million, two hundred forty-four thousand, three hundred eighty".