18021120 has 216 divisors, whose sum is σ = 65416176. Its totient is φ = 4202496.

The previous prime is 18021083. The next prime is 18021131. The reversal of 18021120 is 2112081.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 18021120.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 948471 + ... + 948489.

Almost surely, 2^18021120 is an apocalyptic number.

18021120 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 18021120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32708088).

18021120 is an abundant number, since it is smaller than the sum of its proper divisors (47395056).

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

18021120 is a wasteful number, since it uses less digits than its factorization.

18021120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 18021120 is about 4245.1289733058. The cubic root of 18021120 is about 262.1765994659.

The spelling of 18021120 in words is "eighteen million, twenty-one thousand, one hundred twenty".