720130121 has 2 divisors, whose sum is σ = 720130122. Its totient is φ = 720130120.

The previous prime is 720130079. The next prime is 720130123. The reversal of 720130121 is 121031027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 514609225 + 205520896 = 22685^2 + 14336^2 .

It is a cyclic number.

It is not a de Polignac number, because 720130121 - 2⁶ = 720130057 is a prime.

Together with 720130123, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 720130121.

It is not a weakly prime, because it can be changed into another prime (720130123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360065060 + 360065061.

It is an arithmetic number, because the mean of its divisors is an integer number (360065061).

Almost surely, 2^720130121 is an apocalyptic number.

It is an amenable number.

720130121 is a deficient number, since it is larger than the sum of its proper divisors (1).

720130121 is an equidigital number, since it uses as much as digits as its factorization.

720130121 is an odious number, because the sum of its binary digits is odd.

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

The square root of 720130121 is about 26835.2402821365. The cubic root of 720130121 is about 896.3349391024.

Adding to 720130121 its reverse (121031027), we get a palindrome (841161148).

The spelling of 720130121 in words is "seven hundred twenty million, one hundred thirty thousand, one hundred twenty-one".