18822720 has 112 divisors (see below), whose sum is σ = 68323968. Its totient is φ = 4300800.

The previous prime is 18822697. The next prime is 18822721. The reversal of 18822720 is 2722881.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (18822721) 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 15 ways as a sum of consecutive naturals, for example, 5320 + ... + 8120.

Almost surely, 2^18822720 is an apocalyptic number.

18822720 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 18822720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34161984).

18822720 is an abundant number, since it is smaller than the sum of its proper divisors (49501248).

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

18822720 is a wasteful number, since it uses less digits than its factorization.

18822720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2828 (or 2818 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 18822720 is about 4338.5158752735. The cubic root of 18822720 is about 266.0076504857.

The spelling of 18822720 in words is "eighteen million, eight hundred twenty-two thousand, seven hundred twenty".