18340640 has 48 divisors (see below), whose sum is σ = 43908480. Its totient is φ = 7238400.

The previous prime is 18340639. The next prime is 18340709. The reversal of 18340640 is 4604381.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11915 + ... + 13365.

It is an arithmetic number, because the mean of its divisors is an integer number (914760).

Almost surely, 2^18340640 is an apocalyptic number.

18340640 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 18340640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21954240).

18340640 is an abundant number, since it is smaller than the sum of its proper divisors (25567840).

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

18340640 is a wasteful number, since it uses less digits than its factorization.

18340640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1545 (or 1537 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 18340640 is about 4282.5973427349. The cubic root of 18340640 is about 263.7170215499.

The spelling of 18340640 in words is "eighteen million, three hundred forty thousand, six hundred forty".