18000720 has 120 divisors (see below), whose sum is σ = 63138816. Its totient is φ = 4587264.

The previous prime is 18000709. The next prime is 18000721. The reversal of 18000720 is 2700081.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 18000693 and 18000702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18000721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16017 + ... + 17103.

Almost surely, 2^18000720 is an apocalyptic number.

18000720 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 18000720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31569408).

18000720 is an abundant number, since it is smaller than the sum of its proper divisors (45138096).

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

18000720 is a wasteful number, since it uses less digits than its factorization.

18000720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129 (or 1120 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 18000720 is about 4242.7255390845. The cubic root of 18000720 is about 262.0776336962.

It can be divided in two parts, 18000 and 720, that multiplied together give a 4-th power (12960000 = 60⁴).

The spelling of 18000720 in words is "eighteen million, seven hundred twenty", and thus it is an aban number.