18784221531018 has 16 divisors (see below), whose sum is σ = 38367771638400. Its totient is φ = 6128185747616.

The previous prime is 18784221531007. The next prime is 18784221531059. The reversal of 18784221531018 is 81013512248781.

It is a super-2 number, since 2×18784221531018² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33305357043 + ... + 33305357606.

It is an arithmetic number, because the mean of its divisors is an integer number (2397985727400).

Almost surely, 2^{18784221531018} is an apocalyptic number.

18784221531018 is an abundant number, since it is smaller than the sum of its proper divisors (19583550107382).

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

18784221531018 is a wasteful number, since it uses less digits than its factorization.

18784221531018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66610714701.

The product of its (nonzero) digits is 860160, while the sum is 51.

Adding to 18784221531018 its reverse (81013512248781), we get a palindrome (99797733779799).

The spelling of 18784221531018 in words is "eighteen trillion, seven hundred eighty-four billion, two hundred twenty-one million, five hundred thirty-one thousand, eighteen".