18638430 has 48 divisors (see below), whose sum is σ = 47237904. Its totient is φ = 4705920.

The previous prime is 18638413. The next prime is 18638467. The reversal of 18638430 is 3483681.

It is a junction number, because it is equal to n+sod(n) for n = 18638391 and 18638400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9970 + ... + 11690.

It is an arithmetic number, because the mean of its divisors is an integer number (984123).

Almost surely, 2^18638430 is an apocalyptic number.

18638430 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18638430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23618952).

18638430 is an abundant number, since it is smaller than the sum of its proper divisors (28599474).

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

18638430 is a wasteful number, since it uses less digits than its factorization.

18638430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769 (or 1750 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 18638430 is about 4317.2248030419. The cubic root of 18638430 is about 265.1366567024.

The spelling of 18638430 in words is "eighteen million, six hundred thirty-eight thousand, four hundred thirty".