18123858 has 64 divisors (see below), whose sum is σ = 42462720. Its totient is φ = 5723136.

The previous prime is 18123857. The next prime is 18123877. The reversal of 18123858 is 85832181.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (18123857) 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, 93810 + ... + 94002.

It is an arithmetic number, because the mean of its divisors is an integer number (663480).

Almost surely, 2^18123858 is an apocalyptic number.

18123858 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18123858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21231360).

18123858 is an abundant number, since it is smaller than the sum of its proper divisors (24338862).

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

18123858 is a wasteful number, since it uses less digits than its factorization.

18123858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288 (or 282 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 18123858 is about 4257.2124682708. The cubic root of 18123858 is about 262.6738766376.

It can be divided in two parts, 18123 and 858, that added together give a palindrome (18981).

The spelling of 18123858 in words is "eighteen million, one hundred twenty-three thousand, eight hundred fifty-eight".