18007440 has 160 divisors (see below), whose sum is σ = 64281600. Its totient is φ = 4124160.

The previous prime is 18007361. The next prime is 18007447. The reversal of 18007440 is 4470081.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 18007440.

It is not an unprimeable number, because it can be changed into a prime (18007447) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49981 + ... + 50339.

It is an arithmetic number, because the mean of its divisors is an integer number (401760).

Almost surely, 2^18007440 is an apocalyptic number.

18007440 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 18007440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32140800).

18007440 is an abundant number, since it is smaller than the sum of its proper divisors (46274160).

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

18007440 is a wasteful number, since it uses less digits than its factorization.

18007440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 399 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 18007440 is about 4243.5174089427. The cubic root of 18007440 is about 262.1102424397.

The spelling of 18007440 in words is "eighteen million, seven thousand, four hundred forty".