18440500 has 48 divisors (see below), whose sum is σ = 43387344. Its totient is φ = 6806400.

The previous prime is 18440489. The next prime is 18440501. The reversal of 18440500 is 504481.

It can be written as a sum of positive squares in 8 ways, for example, as 14653584 + 3786916 = 3828^2 + 1946^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18440501) 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, 5082 + ... + 7918.

It is an arithmetic number, because the mean of its divisors is an integer number (903903).

Almost surely, 2^18440500 is an apocalyptic number.

18440500 is a gapful number since it is divisible by the number (10) 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 18440500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21693672).

18440500 is an abundant number, since it is smaller than the sum of its proper divisors (24946844).

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

18440500 is a wasteful number, since it uses less digits than its factorization.

18440500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2869 (or 2857 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 18440500 is about 4294.2403286262. The cubic root of 18440500 is about 264.1947789689.

Adding to 18440500 its reverse (504481), we get a palindrome (18944981).

The spelling of 18440500 in words is "eighteen million, four hundred forty thousand, five hundred".