721733 has 2 divisors, whose sum is σ = 721734. Its totient is φ = 721732.

The previous prime is 721709. The next prime is 721739. The reversal of 721733 is 337127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 708964 + 12769 = 842^2 + 113^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721733 is a prime.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 721699 and 721708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360866 + 360867.

It is an arithmetic number, because the mean of its divisors is an integer number (360867).

2⁷²¹⁷³³ is an apocalyptic number.

It is an amenable number.

721733 is a deficient number, since it is larger than the sum of its proper divisors (1).

721733 is an equidigital number, since it uses as much as digits as its factorization.

721733 is an evil number, because the sum of its binary digits is even.

The product of its digits is 882, while the sum is 23.

The square root of 721733 is about 849.5487037245. The cubic root of 721733 is about 89.6999472621.

The spelling of 721733 in words is "seven hundred twenty-one thousand, seven hundred thirty-three".