18644320 has 48 divisors (see below), whose sum is σ = 46373040. Its totient is φ = 7064064.

The previous prime is 18644317. The next prime is 18644321. The reversal of 18644320 is 2344681.

It is a super-2 number, since 2×18644320² = 695221336524800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18644321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27 + ... + 6106.

It is an arithmetic number, because the mean of its divisors is an integer number (966105).

Almost surely, 2^18644320 is an apocalyptic number.

18644320 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 18644320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23186520).

18644320 is an abundant number, since it is smaller than the sum of its proper divisors (27728720).

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

18644320 is a wasteful number, since it uses less digits than its factorization.

18644320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6167 (or 6159 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 18644320 is about 4317.9069003396. The cubic root of 18644320 is about 265.1645827032.

The spelling of 18644320 in words is "eighteen million, six hundred forty-four thousand, three hundred twenty".