18905140 has 24 divisors (see below), whose sum is σ = 39817512. Its totient is φ = 7539840.

The previous prime is 18905119. The next prime is 18905143. The reversal of 18905140 is 4150981.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17424 + 18887716 = 132^2 + 4346^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18905099 and 18905108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18905143) 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, 6750 + ... + 9130.

It is an arithmetic number, because the mean of its divisors is an integer number (1659063).

Almost surely, 2^18905140 is an apocalyptic number.

18905140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18905140 is an abundant number, since it is smaller than the sum of its proper divisors (20912372).

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

18905140 is a wasteful number, since it uses less digits than its factorization.

18905140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2787 (or 2785 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 18905140 is about 4348.0041398324. The cubic root of 18905140 is about 266.3953455646.

The spelling of 18905140 in words is "eighteen million, nine hundred five thousand, one hundred forty".