721615273 has 2 divisors, whose sum is σ = 721615274. Its totient is φ = 721615272.

The previous prime is 721615247. The next prime is 721615319. The reversal of 721615273 is 372516127.

721615273 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 665485209 + 56130064 = 25797^2 + 7492^2 .

It is an emirp because it is prime and its reverse (372516127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721615273 is a prime.

It is not a weakly prime, because it can be changed into another prime (721615073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360807636 + 360807637.

It is an arithmetic number, because the mean of its divisors is an integer number (360807637).

Almost surely, 2^721615273 is an apocalyptic number.

It is an amenable number.

721615273 is a deficient number, since it is larger than the sum of its proper divisors (1).

721615273 is an equidigital number, since it uses as much as digits as its factorization.

721615273 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17640, while the sum is 34.

The square root of 721615273 is about 26862.8977029657. The cubic root of 721615273 is about 896.9506979826.

The spelling of 721615273 in words is "seven hundred twenty-one million, six hundred fifteen thousand, two hundred seventy-three".