18051440 has 80 divisors (see below), whose sum is σ = 46577376. Its totient is φ = 6451200.

The previous prime is 18051413. The next prime is 18051457. The reversal of 18051440 is 4415081.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

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, 64100 + ... + 64380.

Almost surely, 2^18051440 is an apocalyptic number.

18051440 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 18051440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23288688).

18051440 is an abundant number, since it is smaller than the sum of its proper divisors (28525936).

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

18051440 is a wasteful number, since it uses less digits than its factorization.

18051440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378 (or 372 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 18051440 is about 4248.6986242849. The cubic root of 18051440 is about 262.3235518670.

The spelling of 18051440 in words is "eighteen million, fifty-one thousand, four hundred forty".