18686323181824 has 81 divisors (see below), whose sum is σ = 37827827409099. Its totient is φ = 9212683161600.

The previous prime is 18686323181821. The next prime is 18686323181873. The reversal of 18686323181824 is 42818132368681.

The square root of 18686323181824 is 4322768.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 16734009600 + 18669589172224 = 129360^2 + 4320832^2 .

It is not an unprimeable number, because it can be changed into a prime (18686323181821) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5048991174 + ... + 5048994874.

Almost surely, 2^{18686323181824} is an apocalyptic number.

18686323181824 is the 4322768-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18686323181824

18686323181824 is an abundant number, since it is smaller than the sum of its proper divisors (19141504227275).

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

18686323181824 is an frugal number, since it uses more digits than its factorization.

18686323181824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7564 (or 3776 counting only the distinct ones).

The product of its digits is 21233664, while the sum is 61.

The spelling of 18686323181824 in words is "eighteen trillion, six hundred eighty-six billion, three hundred twenty-three million, one hundred eighty-one thousand, eight hundred twenty-four".