8561816172 has 144 divisors (see below), whose sum is σ = 27256669440. Its totient is φ = 2205512064.

The previous prime is 8561816161. The next prime is 8561816173. The reversal of 8561816172 is 2716181658.

8561816172 is a `hidden beast` number, since 8 + 5 + 618 + 16 + 17 + 2 = 666.

It is not an unprimeable number, because it can be changed into a prime (8561816173) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 110479 + ... + 171257.

Almost surely, 2^8561816172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8561816172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13628334720).

8561816172 is an abundant number, since it is smaller than the sum of its proper divisors (18694853268).

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

8561816172 is a wasteful number, since it uses less digits than its factorization.

8561816172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60852 (or 60847 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 8561816172 is about 92530.0825245498. The cubic root of 8561816172 is about 2045.7629059948.

The spelling of 8561816172 in words is "eight billion, five hundred sixty-one million, eight hundred sixteen thousand, one hundred seventy-two".