16561305135846 has 128 divisors (see below), whose sum is σ = 37984333363200. Its totient is φ = 5345273099520.

The previous prime is 16561305135839. The next prime is 16561305135857. The reversal of 16561305135846 is 64853150316561.

16561305135846 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 1 + 3 + 0 + 51 + 3 + 584 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 16561305135792 and 16561305135801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1185738355 + ... + 1185752321.

It is an arithmetic number, because the mean of its divisors is an integer number (296752604400).

Almost surely, 2^{16561305135846} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16561305135846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18992166681600).

16561305135846 is an abundant number, since it is smaller than the sum of its proper divisors (21423028227354).

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

16561305135846 is a wasteful number, since it uses less digits than its factorization.

16561305135846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18011 (or 18005 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 54.

It can be divided in two parts, 1656130 and 5135846, that added together give a palindrome (6791976).

The spelling of 16561305135846 in words is "sixteen trillion, five hundred sixty-one billion, three hundred five million, one hundred thirty-five thousand, eight hundred forty-six".