18344640 has 112 divisors (see below), whose sum is σ = 59143392. Its totient is φ = 4816896.

The previous prime is 18344603. The next prime is 18344659. The reversal of 18344640 is 4644381.

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

It is a junction number, because it is equal to n+sod(n) for n = 18344598 and 18344607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93022 + ... + 93218.

It is an arithmetic number, because the mean of its divisors is an integer number (528066).

Almost surely, 2^18344640 is an apocalyptic number.

18344640 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 18344640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29571696).

18344640 is an abundant number, since it is smaller than the sum of its proper divisors (40798752).

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

18344640 is a wasteful number, since it uses less digits than its factorization.

18344640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 304 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 18344640 is about 4283.0643235889. The cubic root of 18344640 is about 263.7361919353.

The spelling of 18344640 in words is "eighteen million, three hundred forty-four thousand, six hundred forty".