18459640 has 64 divisors (see below), whose sum is σ = 44323200. Its totient is φ = 6899328.

The previous prime is 18459629. The next prime is 18459641. The reversal of 18459640 is 4695481.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 18459640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18459641) 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, 81207 + ... + 81433.

It is an arithmetic number, because the mean of its divisors is an integer number (692550).

Almost surely, 2^18459640 is an apocalyptic number.

18459640 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 18459640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22161600).

18459640 is an abundant number, since it is smaller than the sum of its proper divisors (25863560).

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

18459640 is a wasteful number, since it uses less digits than its factorization.

18459640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 18459640 is about 4296.4683171181. The cubic root of 18459640 is about 264.2861528394.

The spelling of 18459640 in words is "eighteen million, four hundred fifty-nine thousand, six hundred forty".