18409404 has 48 divisors (see below), whose sum is σ = 48702080. Its totient is φ = 5365440.

The previous prime is 18409393. The next prime is 18409409. The reversal of 18409404 is 40490481.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18409409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142 + ... + 6069.

Almost surely, 2^18409404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18409404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24351040).

18409404 is an abundant number, since it is smaller than the sum of its proper divisors (30292676).

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

18409404 is a wasteful number, since it uses less digits than its factorization.

18409404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6250 (or 6248 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 18409404 is about 4290.6181372851. The cubic root of 18409404 is about 264.0461925599.

Adding to 18409404 its reverse (40490481), we get a palindrome (58899885).

The spelling of 18409404 in words is "eighteen million, four hundred nine thousand, four hundred four".