721319 has 2 divisors, whose sum is σ = 721320. Its totient is φ = 721318.

The previous prime is 721307. The next prime is 721321. The reversal of 721319 is 913127.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721319 is a prime.

It is a super-2 number, since 2×721319² = 1040602199522, which contains 22 as substring.

Together with 721321, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 721294 and 721303.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721319.

It is not a weakly prime, because it can be changed into another prime (721379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360659 + 360660.

It is an arithmetic number, because the mean of its divisors is an integer number (360660).

2⁷²¹³¹⁹ is an apocalyptic number.

721319 is a deficient number, since it is larger than the sum of its proper divisors (1).

721319 is an equidigital number, since it uses as much as digits as its factorization.

721319 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378, while the sum is 23.

The square root of 721319 is about 849.3050099935. The cubic root of 721319 is about 89.6827927738.

The spelling of 721319 in words is "seven hundred twenty-one thousand, three hundred nineteen".