18808640 has 56 divisors (see below), whose sum is σ = 45674280. Its totient is φ = 7374848.

The previous prime is 18808639. The next prime is 18808663. The reversal of 18808640 is 4680881.

It can be written as a sum of positive squares in 4 ways, for example, as 215296 + 18593344 = 464^2 + 4312^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18808640.

It is a congruent number.

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, 16406 + ... + 17514.

Almost surely, 2^18808640 is an apocalyptic number.

18808640 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 18808640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22837140).

18808640 is an abundant number, since it is smaller than the sum of its proper divisors (26865640).

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

18808640 is a wasteful number, since it uses less digits than its factorization.

18808640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1179 (or 1169 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 18808640 is about 4336.8928969943. The cubic root of 18808640 is about 265.9413065142.

The spelling of 18808640 in words is "eighteen million, eight hundred eight thousand, six hundred forty".