18840138 has 16 divisors (see below), whose sum is σ = 38482560. Its totient is φ = 6146336.

The previous prime is 18840137. The next prime is 18840163. The reversal of 18840138 is 83104881.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18840099 and 18840108.

It is not an unprimeable number, because it can be changed into a prime (18840137) 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, 33123 + ... + 33686.

It is an arithmetic number, because the mean of its divisors is an integer number (2405160).

Almost surely, 2^18840138 is an apocalyptic number.

18840138 is an abundant number, since it is smaller than the sum of its proper divisors (19642422).

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

18840138 is a wasteful number, since it uses less digits than its factorization.

18840138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66861.

The product of its (nonzero) digits is 6144, while the sum is 33.

The square root of 18840138 is about 4340.5227795739. The cubic root of 18840138 is about 266.0896771147.

The spelling of 18840138 in words is "eighteen million, eight hundred forty thousand, one hundred thirty-eight".