18728320 has 64 divisors (see below), whose sum is σ = 48237840. Its totient is φ = 6912000.

The previous prime is 18728291. The next prime is 18728321. The reversal of 18728320 is 2382781.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18728321) 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, 7195 + ... + 9445.

Almost surely, 2^18728320 is an apocalyptic number.

18728320 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 18728320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24118920).

18728320 is an abundant number, since it is smaller than the sum of its proper divisors (29509520).

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

18728320 is a wasteful number, since it uses less digits than its factorization.

18728320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2283 (or 2271 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 18728320 is about 4327.6229040895. The cubic root of 18728320 is about 265.5622097489.

It can be divided in two parts, 18 and 728320, that multiplied together give a triangular number (13109760 = T₅₁₂₀).

The spelling of 18728320 in words is "eighteen million, seven hundred twenty-eight thousand, three hundred twenty".