8161440768 has 462 divisors, whose sum is σ = 27282501974. Its totient is φ = 2424619008.

The previous prime is 8161440761. The next prime is 8161440811. The reversal of 8161440768 is 8670441618.

8161440768 is a `hidden beast` number, since 81 + 61 + 440 + 76 + 8 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 394896384 + 7766544384 = 19872^2 + 88128^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8161440761) by changing a digit.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 281428978 + ... + 281429006.

Almost surely, 2^8161440768 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 8161440768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13641250987).

8161440768 is an abundant number, since it is smaller than the sum of its proper divisors (19121061206).

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

8161440768 is an equidigital number, since it uses as much as digits as its factorization.

8161440768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 8161440768 is about 90340.6927580257. The cubic root of 8161440768 is about 2013.3639015090.

The spelling of 8161440768 in words is "eight billion, one hundred sixty-one million, four hundred forty thousand, seven hundred sixty-eight".