725187809 has 2 divisors, whose sum is σ = 725187810. Its totient is φ = 725187808.

The previous prime is 725187803. The next prime is 725187871. The reversal of 725187809 is 908781527.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 636300625 + 88887184 = 25225^2 + 9428^2 .

It is an emirp because it is prime and its reverse (908781527) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 725187809 - 2²⁰ = 724139233 is a prime.

It is not a weakly prime, because it can be changed into another prime (725187803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 362593904 + 362593905.

It is an arithmetic number, because the mean of its divisors is an integer number (362593905).

Almost surely, 2^725187809 is an apocalyptic number.

It is an amenable number.

725187809 is a deficient number, since it is larger than the sum of its proper divisors (1).

725187809 is an equidigital number, since it uses as much as digits as its factorization.

725187809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 282240, while the sum is 47.

The square root of 725187809 is about 26929.3113354204. The cubic root of 725187809 is about 898.4284545442.

The spelling of 725187809 in words is "seven hundred twenty-five million, one hundred eighty-seven thousand, eight hundred nine".