16521100018 has 8 divisors (see below), whose sum is σ = 24783540012. Its totient is φ = 8259920016.

The previous prime is 16521100009. The next prime is 16521100033. The reversal of 16521100018 is 81000112561.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15333125929 + 1187974089 = 123827^2 + 34467^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 16521099965 and 16521100001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281505 + ... + 335092.

Almost surely, 2^16521100018 is an apocalyptic number.

16521100018 is a deficient number, since it is larger than the sum of its proper divisors (8262439994).

16521100018 is a wasteful number, since it uses less digits than its factorization.

16521100018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629996.

The product of its (nonzero) digits is 480, while the sum is 25.

Adding to 16521100018 its reverse (81000112561), we get a palindrome (97521212579).

The spelling of 16521100018 in words is "sixteen billion, five hundred twenty-one million, one hundred thousand, eighteen".