725905 has 8 divisors (see below), whose sum is σ = 892584. Its totient is φ = 566400.

The previous prime is 725897. The next prime is 725909. The reversal of 725905 is 509527.

It is a Cunningham number, because it is equal to 852²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1 + 725904 = 1^2 + 852^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 725905 - 2³ = 725897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (725909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1566 + ... + 1975.

It is an arithmetic number, because the mean of its divisors is an integer number (111573).

2⁷²⁵⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

725905 is a deficient number, since it is larger than the sum of its proper divisors (166679).

725905 is a wasteful number, since it uses less digits than its factorization.

725905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3587.

The product of its (nonzero) digits is 3150, while the sum is 28.

The square root of 725905 is about 852.0005868543. Note that the first 3 decimals coincide. The cubic root of 725905 is about 89.8724530723.

The spelling of 725905 in words is "seven hundred twenty-five thousand, nine hundred five".