18817540 has 48 divisors (see below), whose sum is σ = 45424512. Its totient is φ = 6414336.

The previous prime is 18817517. The next prime is 18817541. The reversal of 18817540 is 4571881.

It is a junction number, because it is equal to n+sod(n) for n = 18817496 and 18817505.

It is not an unprimeable number, because it can be changed into a prime (18817541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35719 + ... + 36241.

It is an arithmetic number, because the mean of its divisors is an integer number (946344).

Almost surely, 2^18817540 is an apocalyptic number.

18817540 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 18817540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22712256).

18817540 is an abundant number, since it is smaller than the sum of its proper divisors (26606972).

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

18817540 is a wasteful number, since it uses less digits than its factorization.

18817540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796 (or 794 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 18817540 is about 4337.9188558570. The cubic root of 18817540 is about 265.9832465375.

The spelling of 18817540 in words is "eighteen million, eight hundred seventeen thousand, five hundred forty".