721505219 has 2 divisors, whose sum is σ = 721505220. Its totient is φ = 721505218.

The previous prime is 721505203. The next prime is 721505227. The reversal of 721505219 is 912505127.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (912505127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721505219 - 2⁴ = 721505203 is a prime.

It is a super-2 number, since 2×721505219² = 1041139562088475922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721505119) 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, 360752609 + 360752610.

It is an arithmetic number, because the mean of its divisors is an integer number (360752610).

Almost surely, 2^721505219 is an apocalyptic number.

721505219 is a deficient number, since it is larger than the sum of its proper divisors (1).

721505219 is an equidigital number, since it uses as much as digits as its factorization.

721505219 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6300, while the sum is 32.

The square root of 721505219 is about 26860.8491861296. The cubic root of 721505219 is about 896.9050974922.

The spelling of 721505219 in words is "seven hundred twenty-one million, five hundred five thousand, two hundred nineteen".