18216821338 has 8 divisors (see below), whose sum is σ = 28206691200. Its totient is φ = 8814590940.

The previous prime is 18216821323. The next prime is 18216821339. The reversal of 18216821338 is 83312861281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×18216821338² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18216821294 and 18216821303.

It is not an unprimeable number, because it can be changed into a prime (18216821339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146909788 + ... + 146909911.

It is an arithmetic number, because the mean of its divisors is an integer number (3525836400).

Almost surely, 2^18216821338 is an apocalyptic number.

18216821338 is a deficient number, since it is larger than the sum of its proper divisors (9989869862).

18216821338 is a wasteful number, since it uses less digits than its factorization.

18216821338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293819732.

The product of its digits is 110592, while the sum is 43.

The spelling of 18216821338 in words is "eighteen billion, two hundred sixteen million, eight hundred twenty-one thousand, three hundred thirty-eight".