18945438720 has 352 divisors, whose sum is σ = 66138078720. Its totient is φ = 4600627200.

The previous prime is 18945438713. The next prime is 18945438737. The reversal of 18945438720 is 2783454981.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15774120 + ... + 15775320.

Almost surely, 2^18945438720 is an apocalyptic number.

18945438720 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 18945438720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33069039360).

18945438720 is an abundant number, since it is smaller than the sum of its proper divisors (47192640000).

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

18945438720 is a wasteful number, since it uses less digits than its factorization.

18945438720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1321 (or 1303 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 51.

The spelling of 18945438720 in words is "eighteen billion, nine hundred forty-five million, four hundred thirty-eight thousand, seven hundred twenty".