18504978159968 has 96 divisors (see below), whose sum is σ = 37990522209024. Its totient is φ = 8864973891072.

The previous prime is 18504978159961. The next prime is 18504978159991. The reversal of 18504978159968 is 86995187940581.

It is a super-2 number, since 2×18504978159968² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18504978159892 and 18504978159901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18504978159961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29862821 + ... + 30476187.

It is an arithmetic number, because the mean of its divisors is an integer number (395734606344).

Almost surely, 2^{18504978159968} 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 18504978159968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18995261104512).

18504978159968 is an abundant number, since it is smaller than the sum of its proper divisors (19485544049056).

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

18504978159968 is a wasteful number, since it uses less digits than its factorization.

18504978159968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613804 (or 613796 counting only the distinct ones).

The product of its (nonzero) digits is 1567641600, while the sum is 80.

The spelling of 18504978159968 in words is "eighteen trillion, five hundred four billion, nine hundred seventy-eight million, one hundred fifty-nine thousand, nine hundred sixty-eight".