18288640 has 104 divisors (see below), whose sum is σ = 47180160. Its totient is φ = 6782976.

The previous prime is 18288637. The next prime is 18288649. The reversal of 18288640 is 4688281.

It is a self number, because there is not a number n which added to its sum of digits gives 18288640.

It is not an unprimeable number, because it can be changed into a prime (18288649) 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, 389097 + ... + 389143.

Almost surely, 2^18288640 is an apocalyptic number.

18288640 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 18288640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23590080).

18288640 is an abundant number, since it is smaller than the sum of its proper divisors (28891520).

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

18288640 is an equidigital number, since it uses as much as digits as its factorization.

18288640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 18288640 is about 4276.5219513058. The cubic root of 18288640 is about 263.4675525075.

It can be divided in two parts, 1 and 8288640, that added together give a square (8288641 = 2879²).

The spelling of 18288640 in words is "eighteen million, two hundred eighty-eight thousand, six hundred forty".