721333 has 2 divisors, whose sum is σ = 721334. Its totient is φ = 721332.

The previous prime is 721321. The next prime is 721337. The reversal of 721333 is 333127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 432964 + 288369 = 658^2 + 537^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721333 is a prime.

It is equal to p₅₈₁₄₁ and since 721333 and 58141 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 721333.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360666 + 360667.

It is an arithmetic number, because the mean of its divisors is an integer number (360667).

2⁷²¹³³³ is an apocalyptic number.

It is an amenable number.

721333 is a deficient number, since it is larger than the sum of its proper divisors (1).

721333 is an equidigital number, since it uses as much as digits as its factorization.

721333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378, while the sum is 19.

The square root of 721333 is about 849.3132519866. The cubic root of 721333 is about 89.6833729845.

It can be divided in two parts, 7 and 21333, that multiplied together give a triangular number (149331 = T₅₄₆).

The spelling of 721333 in words is "seven hundred twenty-one thousand, three hundred thirty-three".