720005161 has 2 divisors, whose sum is σ = 720005162. Its totient is φ = 720005160.

The previous prime is 720005137. The next prime is 720005197. The reversal of 720005161 is 161500027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 705221136 + 14784025 = 26556^2 + 3845^2 .

It is a cyclic number.

It is not a de Polignac number, because 720005161 - 2⁵ = 720005129 is a prime.

It is not a weakly prime, because it can be changed into another prime (720005761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360002580 + 360002581.

It is an arithmetic number, because the mean of its divisors is an integer number (360002581).

Almost surely, 2^720005161 is an apocalyptic number.

It is an amenable number.

720005161 is a deficient number, since it is larger than the sum of its proper divisors (1).

720005161 is an equidigital number, since it uses as much as digits as its factorization.

720005161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 720005161 is about 26832.9118993821. The cubic root of 720005161 is about 896.2830908369.

Adding to 720005161 its reverse (161500027), we get a palindrome (881505188).

The spelling of 720005161 in words is "seven hundred twenty million, five thousand, one hundred sixty-one".