18538780 has 48 divisors (see below), whose sum is σ = 42364224. Its totient is φ = 6773760.

The previous prime is 18538777. The next prime is 18538783. The reversal of 18538780 is 8783581.

It is an interprime number because it is at equal distance from previous prime (18538777) and next prime (18538783).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18538783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29065 + ... + 29695.

It is an arithmetic number, because the mean of its divisors is an integer number (882588).

Almost surely, 2^18538780 is an apocalyptic number.

18538780 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 18538780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21182112).

18538780 is an abundant number, since it is smaller than the sum of its proper divisors (23825444).

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

18538780 is a wasteful number, since it uses less digits than its factorization.

18538780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766 (or 764 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 40.

The square root of 18538780 is about 4305.6683569453. The cubic root of 18538780 is about 264.6632961168.

The spelling of 18538780 in words is "eighteen million, five hundred thirty-eight thousand, seven hundred eighty".