9161720389 has 2 divisors, whose sum is σ = 9161720390. Its totient is φ = 9161720388.

The previous prime is 9161720363. The next prime is 9161720417. The reversal of 9161720389 is 9830271619.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8966196100 + 195524289 = 94690^2 + 13983^2 .

It is a cyclic number.

It is not a de Polignac number, because 9161720389 - 2⁷ = 9161720261 is a prime.

It is a super-2 number, since 2×9161720389² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9161720329) 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 as a sum of consecutive naturals, namely, 4580860194 + 4580860195.

It is an arithmetic number, because the mean of its divisors is an integer number (4580860195).

Almost surely, 2^9161720389 is an apocalyptic number.

It is an amenable number.

9161720389 is a deficient number, since it is larger than the sum of its proper divisors (1).

9161720389 is an equidigital number, since it uses as much as digits as its factorization.

9161720389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 9161720389 is about 95716.8761974606. The cubic root of 9161720389 is about 2092.4688961251.

The spelling of 9161720389 in words is "nine billion, one hundred sixty-one million, seven hundred twenty thousand, three hundred eighty-nine".