18789440 has 56 divisors (see below), whose sum is σ = 45427392. Its totient is φ = 7400960.

The previous prime is 18789431. The next prime is 18789443. The reversal of 18789440 is 4498781.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (18789443) 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, 22307 + ... + 23133.

Almost surely, 2^18789440 is an apocalyptic number.

18789440 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 18789440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22713696).

18789440 is an abundant number, since it is smaller than the sum of its proper divisors (26637952).

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

18789440 is an equidigital number, since it uses as much as digits as its factorization.

18789440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915 (or 905 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 18789440 is about 4334.6787654912. The cubic root of 18789440 is about 265.8507840821.

The spelling of 18789440 in words is "eighteen million, seven hundred eighty-nine thousand, four hundred forty".