18016720 has 40 divisors (see below), whose sum is σ = 42280776. Its totient is φ = 7139328.

The previous prime is 18016717. The next prime is 18016721. The reversal of 18016720 is 2761081.

It can be written as a sum of positive squares in 4 ways, for example, as 242064 + 17774656 = 492^2 + 4216^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18016721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8044 + ... + 10036.

Almost surely, 2^18016720 is an apocalyptic number.

18016720 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 18016720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21140388).

18016720 is an abundant number, since it is smaller than the sum of its proper divisors (24264056).

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

18016720 is a wasteful number, since it uses less digits than its factorization.

18016720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2119 (or 2113 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 18016720 is about 4244.6107006415. The cubic root of 18016720 is about 262.1552602274.

It can be divided in two parts, 180 and 16720, that added together give a square (16900 = 130²).

The spelling of 18016720 in words is "eighteen million, sixteen thousand, seven hundred twenty".