18303440 has 20 divisors (see below), whose sum is σ = 42555684. Its totient is φ = 7321344.

The previous prime is 18303427. The next prime is 18303449. The reversal of 18303440 is 4430381.

It can be written as a sum of positive squares in 2 ways, for example, as 5400976 + 12902464 = 2324^2 + 3592^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18303449) 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 3 ways as a sum of consecutive naturals, for example, 114317 + ... + 114476.

Almost surely, 2^18303440 is an apocalyptic number.

18303440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18303440 is an abundant number, since it is smaller than the sum of its proper divisors (24252244).

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

18303440 is a wasteful number, since it uses less digits than its factorization.

18303440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228806 (or 228800 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 18303440 is about 4278.2519794888. The cubic root of 18303440 is about 263.5386033240.

The spelling of 18303440 in words is "eighteen million, three hundred three thousand, four hundred forty".