725209 has 2 divisors, whose sum is σ = 725210. Its totient is φ = 725208.

The previous prime is 725201. The next prime is 725273. The reversal of 725209 is 902527.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 635209 + 90000 = 797^2 + 300^2 .

It is a cyclic number.

It is not a de Polignac number, because 725209 - 2³ = 725201 is a prime.

It is a d-powerful number, because it can be written as 7³ + 2¹⁶ + 2¹⁸ + 5⁸ + 0 + 9⁴ .

It is not a weakly prime, because it can be changed into another prime (725201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 362604 + 362605.

It is an arithmetic number, because the mean of its divisors is an integer number (362605).

2⁷²⁵²⁰⁹ is an apocalyptic number.

It is an amenable number.

725209 is a deficient number, since it is larger than the sum of its proper divisors (1).

725209 is an equidigital number, since it uses as much as digits as its factorization.

725209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 725209 is about 851.5920384785. The cubic root of 725209 is about 89.8437205570.

It can be divided in two parts, 725 and 209, that multiplied together give a triangular number (151525 = T₅₅₀).

The spelling of 725209 in words is "seven hundred twenty-five thousand, two hundred nine".