720000161 has 2 divisors, whose sum is σ = 720000162. Its totient is φ = 720000160.

The previous prime is 720000107. The next prime is 720000173. The reversal of 720000161 is 161000027.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 538936225 + 181063936 = 23215^2 + 13456^2 .

It is a cyclic number.

It is not a de Polignac number, because 720000161 - 2¹⁸ = 719738017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (720000461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360000080 + 360000081.

It is an arithmetic number, because the mean of its divisors is an integer number (360000081).

Almost surely, 2^720000161 is an apocalyptic number.

It is an amenable number.

720000161 is a deficient number, since it is larger than the sum of its proper divisors (1).

720000161 is an equidigital number, since it uses as much as digits as its factorization.

720000161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 720000161 is about 26832.8187300552. The cubic root of 720000161 is about 896.2810161176.

Adding to 720000161 its reverse (161000027), we get a palindrome (881000188).

The spelling of 720000161 in words is "seven hundred twenty million, one hundred sixty-one", and thus it is an aban number.