720829 has 2 divisors, whose sum is σ = 720830. Its totient is φ = 720828.

The previous prime is 720793. The next prime is 720847. The reversal of 720829 is 928027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 632025 + 88804 = 795^2 + 298^2 .

It is a cyclic number.

It is not a de Polignac number, because 720829 - 2¹⁹ = 196541 is a prime.

720829 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 720797 and 720806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (720869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360414 + 360415.

It is an arithmetic number, because the mean of its divisors is an integer number (360415).

2⁷²⁰⁸²⁹ is an apocalyptic number.

It is an amenable number.

720829 is a deficient number, since it is larger than the sum of its proper divisors (1).

720829 is an equidigital number, since it uses as much as digits as its factorization.

720829 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 720829 is about 849.0164898281. The cubic root of 720829 is about 89.6624806683.

Subtracting from 720829 its sum of digits (28), we obtain a square (720801 = 849²).

The spelling of 720829 in words is "seven hundred twenty thousand, eight hundred twenty-nine".