9161720369 has 4 divisors (see below), whose sum is σ = 9186282996. Its totient is φ = 9137157744.

The previous prime is 9161720363. The next prime is 9161720389. The reversal of 9161720369 is 9630271619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9630271619 = 19 ⋅506856401.

It can be written as a sum of positive squares in 2 ways, for example, as 1934680225 + 7227040144 = 43985^2 + 85012^2 .

It is a cyclic number.

It is not a de Polignac number, because 9161720369 - 2⁴ = 9161720353 is a prime.

It is a super-2 number, since 2×9161720369² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9161720363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12280754 + ... + 12281499.

It is an arithmetic number, because the mean of its divisors is an integer number (2296570749).

Almost surely, 2^9161720369 is an apocalyptic number.

It is an amenable number.

9161720369 is a deficient number, since it is larger than the sum of its proper divisors (24562627).

9161720369 is a wasteful number, since it uses less digits than its factorization.

9161720369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24562626.

The product of its (nonzero) digits is 122472, while the sum is 44.

The square root of 9161720369 is about 95716.8760929858. The cubic root of 9161720369 is about 2092.4688946024.

The spelling of 9161720369 in words is "nine billion, one hundred sixty-one million, seven hundred twenty thousand, three hundred sixty-nine".