720961 has 2 divisors, whose sum is σ = 720962. Its totient is φ = 720960.

The previous prime is 720947. The next prime is 720971. The reversal of 720961 is 169027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 591361 + 129600 = 769^2 + 360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-720961 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (720901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360480 + 360481.

It is an arithmetic number, because the mean of its divisors is an integer number (360481).

2⁷²⁰⁹⁶¹ is an apocalyptic number.

It is an amenable number.

720961 is a deficient number, since it is larger than the sum of its proper divisors (1).

720961 is an equidigital number, since it uses as much as digits as its factorization.

720961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 720961 is about 849.0942232756. The cubic root of 720961 is about 89.6679534064.

Adding to 720961 its reverse (169027), we get a palindrome (889988).

It can be divided in two parts, 720 and 961, that added together give a square (1681 = 41²).

The spelling of 720961 in words is "seven hundred twenty thousand, nine hundred sixty-one".