18720533328 has 160 divisors (see below), whose sum is σ = 57355733760. Its totient is φ = 5148057600.

The previous prime is 18720533327. The next prime is 18720533371. The reversal of 18720533328 is 82333502781.

It is a Cunningham number, because it is equal to 136823²-1.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 18720533328.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18720533327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3280878 + ... + 3286578.

It is an arithmetic number, because the mean of its divisors is an integer number (358473336).

Almost surely, 2^18720533328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18720533328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28677866880).

18720533328 is an abundant number, since it is smaller than the sum of its proper divisors (38635200432).

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

18720533328 is a wasteful number, since it uses less digits than its factorization.

18720533328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6085 (or 6079 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The spelling of 18720533328 in words is "eighteen billion, seven hundred twenty million, five hundred thirty-three thousand, three hundred twenty-eight".