721648073 has 2 divisors, whose sum is σ = 721648074. Its totient is φ = 721648072.

The previous prime is 721648049. The next prime is 721648097. The reversal of 721648073 is 370846127.

721648073 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (721648049) and next prime (721648097).

It can be written as a sum of positive squares in only one way, i.e., 658794889 + 62853184 = 25667^2 + 7928^2 .

It is an emirp because it is prime and its reverse (370846127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721648073 - 2⁶ = 721648009 is a prime.

It is a super-2 number, since 2×721648073² = 1041551882529226658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721648003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360824036 + 360824037.

It is an arithmetic number, because the mean of its divisors is an integer number (360824037).

Almost surely, 2^721648073 is an apocalyptic number.

It is an amenable number.

721648073 is a deficient number, since it is larger than the sum of its proper divisors (1).

721648073 is an equidigital number, since it uses as much as digits as its factorization.

721648073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 38.

The square root of 721648073 is about 26863.5082035091. The cubic root of 721648073 is about 896.9642876511.

The spelling of 721648073 in words is "seven hundred twenty-one million, six hundred forty-eight thousand, seventy-three".