18993540 has 48 divisors (see below), whose sum is σ = 55984320. Its totient is φ = 4798080.

The previous prime is 18993523. The next prime is 18993553. The reversal of 18993540 is 4539981.

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, 7191 + ... + 9470.

It is an arithmetic number, because the mean of its divisors is an integer number (1166340).

Almost surely, 2^18993540 is an apocalyptic number.

18993540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18993540 is an abundant number, since it is smaller than the sum of its proper divisors (36990780).

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

18993540 is a wasteful number, since it uses less digits than its factorization.

18993540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16692 (or 16690 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 18993540 is about 4358.1578677235. The cubic root of 18993540 is about 266.8099195588.

The spelling of 18993540 in words is "eighteen million, nine hundred ninety-three thousand, five hundred forty".