18905440 has 48 divisors (see below), whose sum is σ = 44988048. Its totient is φ = 7507456.

The previous prime is 18905431. The next prime is 18905441. The reversal of 18905440 is 4450981.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18905441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27339 + ... + 28021.

It is an arithmetic number, because the mean of its divisors is an integer number (937251).

Almost surely, 2^18905440 is an apocalyptic number.

18905440 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 18905440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22494024).

18905440 is an abundant number, since it is smaller than the sum of its proper divisors (26082608).

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

18905440 is a wasteful number, since it uses less digits than its factorization.

18905440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 871 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 18905440 is about 4348.0386382828. The cubic root of 18905440 is about 266.3967546731.

The spelling of 18905440 in words is "eighteen million, nine hundred five thousand, four hundred forty".