18323640 has 96 divisors (see below), whose sum is σ = 62169120. Its totient is φ = 4671744.

The previous prime is 18323623. The next prime is 18323647. The reversal of 18323640 is 4632381.

It is a happy number.

18323640 is a `hidden beast` number, since 18 + 3 + 2 + 3 + 640 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18323647) 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, 7174 + ... + 9386.

It is an arithmetic number, because the mean of its divisors is an integer number (647595).

Almost surely, 2^18323640 is an apocalyptic number.

18323640 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 18323640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31084560).

18323640 is an abundant number, since it is smaller than the sum of its proper divisors (43845480).

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

18323640 is a wasteful number, since it uses less digits than its factorization.

18323640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2253 (or 2246 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 18323640 is about 4280.6121057624. The cubic root of 18323640 is about 263.6355163018.

The spelling of 18323640 in words is "eighteen million, three hundred twenty-three thousand, six hundred forty".