18138720 has 192 divisors, whose sum is σ = 62705664. Its totient is φ = 4392960.

The previous prime is 18138713. The next prime is 18138721. The reversal of 18138720 is 2783181.

It is a happy number.

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 (18138721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 342214 + ... + 342266.

It is an arithmetic number, because the mean of its divisors is an integer number (326592).

Almost surely, 2^18138720 is an apocalyptic number.

18138720 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 18138720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31352832).

18138720 is an abundant number, since it is smaller than the sum of its proper divisors (44566944).

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

18138720 is a wasteful number, since it uses less digits than its factorization.

18138720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 18138720 is about 4258.9576189486. The cubic root of 18138720 is about 262.7456566555.

The spelling of 18138720 in words is "eighteen million, one hundred thirty-eight thousand, seven hundred twenty".