18408416 has 96 divisors (see below), whose sum is σ = 43817760. Its totient is φ = 7520256.

The previous prime is 18408391. The next prime is 18408419. The reversal of 18408416 is 61480481.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18408419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134300 + ... + 134436.

It is an arithmetic number, because the mean of its divisors is an integer number (456435).

Almost surely, 2^18408416 is an apocalyptic number.

18408416 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18408416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21908880).

18408416 is an abundant number, since it is smaller than the sum of its proper divisors (25409344).

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

18408416 is a wasteful number, since it uses less digits than its factorization.

18408416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 18408416 is about 4290.5030008147. The cubic root of 18408416 is about 264.0414688454.

Adding to 18408416 its reverse (61480481), we get a palindrome (79888897).

The spelling of 18408416 in words is "eighteen million, four hundred eight thousand, four hundred sixteen".