18123840 has 336 divisors, whose sum is σ = 76078080. Its totient is φ = 3870720.

The previous prime is 18123829. The next prime is 18123857. The reversal of 18123840 is 4832181.

It is a tau number, because it is divible by the number of its divisors (336).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 584625 + ... + 584655.

Almost surely, 2^18123840 is an apocalyptic number.

18123840 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 18123840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38039040).

18123840 is an abundant number, since it is smaller than the sum of its proper divisors (57954240).

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

18123840 is a wasteful number, since it uses less digits than its factorization.

18123840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 18123840 is about 4257.2103542108. The cubic root of 18123840 is about 262.6737896780.

The spelling of 18123840 in words is "eighteen million, one hundred twenty-three thousand, eight hundred forty".