18478390 has 48 divisors (see below), whose sum is σ = 39636432. Its totient is φ = 6181056.

The previous prime is 18478367. The next prime is 18478391. The reversal of 18478390 is 9387481.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18478391) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20632 + ... + 21508.

It is an arithmetic number, because the mean of its divisors is an integer number (825759).

Almost surely, 2^18478390 is an apocalyptic number.

18478390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18478390 is an abundant number, since it is smaller than the sum of its proper divisors (21158042).

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

18478390 is a wasteful number, since it uses less digits than its factorization.

18478390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941 (or 934 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 18478390 is about 4298.6497880148. The cubic root of 18478390 is about 264.3756036366.

Subtracting from 18478390 its reverse (9387481), we obtain a palindrome (9090909).

The spelling of 18478390 in words is "eighteen million, four hundred seventy-eight thousand, three hundred ninety".