16561002218 has 16 divisors (see below), whose sum is σ = 26527080960. Its totient is φ = 7737063600.

The previous prime is 16561002209. The next prime is 16561002229. The reversal of 16561002218 is 81220016561.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4603598 + ... + 4607193.

It is an arithmetic number, because the mean of its divisors is an integer number (1657942560).

Almost surely, 2^16561002218 is an apocalyptic number.

16561002218 is a deficient number, since it is larger than the sum of its proper divisors (9966078742).

16561002218 is a wasteful number, since it uses less digits than its factorization.

16561002218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9210853.

The product of its (nonzero) digits is 5760, while the sum is 32.

Adding to 16561002218 its reverse (81220016561), we get a palindrome (97781018779).

The spelling of 16561002218 in words is "sixteen billion, five hundred sixty-one million, two thousand, two hundred eighteen".