18816720 has 160 divisors (see below), whose sum is σ = 64912512. Its totient is φ = 4478976.

The previous prime is 18816719. The next prime is 18816751. The reversal of 18816720 is 2761881.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115359 + ... + 115521.

Almost surely, 2^18816720 is an apocalyptic number.

18816720 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 18816720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32456256).

18816720 is an abundant number, since it is smaller than the sum of its proper divisors (46095792).

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

18816720 is a wasteful number, since it uses less digits than its factorization.

18816720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229 (or 223 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 18816720 is about 4337.8243394587. The cubic root of 18816720 is about 265.9793829537.

The spelling of 18816720 in words is "eighteen million, eight hundred sixteen thousand, seven hundred twenty".