18533840 has 80 divisors (see below), whose sum is σ = 47246976. Its totient is φ = 6720000.

The previous prime is 18533833. The next prime is 18533849. The reversal of 18533840 is 4833581.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 18533797 and 18533806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18533849) 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, 73715 + ... + 73965.

Almost surely, 2^18533840 is an apocalyptic number.

18533840 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 18533840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23623488).

18533840 is an abundant number, since it is smaller than the sum of its proper divisors (28713136).

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

18533840 is a wasteful number, since it uses less digits than its factorization.

18533840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 18533840 is about 4305.0946563345. The cubic root of 18533840 is about 264.6397858889.

The spelling of 18533840 in words is "eighteen million, five hundred thirty-three thousand, eight hundred forty".