18205440 has 144 divisors (see below), whose sum is σ = 63576576. Its totient is φ = 4403200.

The previous prime is 18205433. The next prime is 18205457. The reversal of 18205440 is 4450281.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 18205440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42025 + ... + 42455.

It is an arithmetic number, because the mean of its divisors is an integer number (441504).

Almost surely, 2^18205440 is an apocalyptic number.

18205440 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 18205440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31788288).

18205440 is an abundant number, since it is smaller than the sum of its proper divisors (45371136).

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

18205440 is a wasteful number, since it uses less digits than its factorization.

18205440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466 (or 452 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 18205440 is about 4266.7833317383. The cubic root of 18205440 is about 263.0674165869.

It can be divided in two parts, 1820 and 5440, that added together give a triangular number (7260 = T₁₂₀).

The spelling of 18205440 in words is "eighteen million, two hundred five thousand, four hundred forty".