721375513 has 2 divisors, whose sum is σ = 721375514. Its totient is φ = 721375512.

The previous prime is 721375429. The next prime is 721375531. The reversal of 721375513 is 315573127.

Together with next prime (721375531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 640950489 + 80425024 = 25317^2 + 8968^2 .

It is a cyclic number.

It is not a de Polignac number, because 721375513 - 2⁹ = 721375001 is a prime.

It is not a weakly prime, because it can be changed into another prime (721375583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360687756 + 360687757.

It is an arithmetic number, because the mean of its divisors is an integer number (360687757).

Almost surely, 2^721375513 is an apocalyptic number.

It is an amenable number.

721375513 is a deficient number, since it is larger than the sum of its proper divisors (1).

721375513 is an equidigital number, since it uses as much as digits as its factorization.

721375513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22050, while the sum is 34.

The square root of 721375513 is about 26858.4346714398. The cubic root of 721375513 is about 896.8513483110.

The spelling of 721375513 in words is "seven hundred twenty-one million, three hundred seventy-five thousand, five hundred thirteen".