18409472 has 48 divisors (see below), whose sum is σ = 37592100. Its totient is φ = 9011200.

The previous prime is 18409459. The next prime is 18409481. The reversal of 18409472 is 27490481.

It can be written as a sum of positive squares in 2 ways, for example, as 18113536 + 295936 = 4256^2 + 544^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182222 + ... + 182322.

Almost surely, 2^18409472 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 18409472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18796050).

18409472 is an abundant number, since it is smaller than the sum of its proper divisors (19182628).

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

18409472 is an equidigital number, since it uses as much as digits as its factorization.

18409472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 18409472 is about 4290.6260615439. The cubic root of 18409472 is about 264.0465176677.

It can be divided in two parts, 18409 and 472, that added together give a palindrome (18881).

The spelling of 18409472 in words is "eighteen million, four hundred nine thousand, four hundred seventy-two".