18020208440 has 128 divisors (see below), whose sum is σ = 44241724800. Its totient is φ = 6566123520.

The previous prime is 18020208421. The next prime is 18020208443. The reversal of 18020208440 is 4480202081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18020208443) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27261710 + ... + 27262370.

It is an arithmetic number, because the mean of its divisors is an integer number (345638475).

Almost surely, 2^18020208440 is an apocalyptic number.

18020208440 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 18020208440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22120862400).

18020208440 is an abundant number, since it is smaller than the sum of its proper divisors (26221516360).

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

18020208440 is a wasteful number, since it uses less digits than its factorization.

18020208440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1297 (or 1293 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The spelling of 18020208440 in words is "eighteen billion, twenty million, two hundred eight thousand, four hundred forty".