18917289984 has 104 divisors (see below), whose sum is σ = 51152729472. Its totient is φ = 6216663040.

The previous prime is 18917289983. The next prime is 18917290013. The reversal of 18917289984 is 48998271981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18917289983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 861607 + ... + 883289.

It is an arithmetic number, because the mean of its divisors is an integer number (491853168).

Almost surely, 2^18917289984 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 18917289984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25576364736).

18917289984 is an abundant number, since it is smaller than the sum of its proper divisors (32235439488).

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

18917289984 is an equidigital number, since it uses as much as digits as its factorization.

18917289984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21781 (or 21759 counting only the distinct ones).

The product of its digits is 20901888, while the sum is 66.

The spelling of 18917289984 in words is "eighteen billion, nine hundred seventeen million, two hundred eighty-nine thousand, nine hundred eighty-four".