8161736644 has 24 divisors (see below), whose sum is σ = 14386743000. Its totient is φ = 4051269120.

The previous prime is 8161736641. The next prime is 8161736659. The reversal of 8161736644 is 4466371618.

It can be written as a sum of positive squares in 4 ways, for example, as 1258120900 + 6903615744 = 35470^2 + 83088^2 .

It is a super-2 number, since 2×8161736644² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 8161736594 and 8161736603.

It is not an unprimeable number, because it can be changed into a prime (8161736641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1922364 + ... + 1926604.

It is an arithmetic number, because the mean of its divisors is an integer number (599447625).

Almost surely, 2^8161736644 is an apocalyptic number.

It is an amenable number.

8161736644 is a deficient number, since it is larger than the sum of its proper divisors (6225006356).

8161736644 is a wasteful number, since it uses less digits than its factorization.

8161736644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7623 (or 7621 counting only the distinct ones).

The product of its digits is 580608, while the sum is 46.

The square root of 8161736644 is about 90342.3302998102. The cubic root of 8161736644 is about 2013.3882313169.

The spelling of 8161736644 in words is "eight billion, one hundred sixty-one million, seven hundred thirty-six thousand, six hundred forty-four".