725765561 has 2 divisors, whose sum is σ = 725765562. Its totient is φ = 725765560.

The previous prime is 725765539. The next prime is 725765597. The reversal of 725765561 is 165567527.

725765561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 377719225 + 348046336 = 19435^2 + 18656^2 .

It is a cyclic number.

It is not a de Polignac number, because 725765561 - 2¹⁴ = 725749177 is a prime.

It is a Chen prime.

It is equal to p_37516967 and since 725765561 and 37516967 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (725762561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 362882780 + 362882781.

It is an arithmetic number, because the mean of its divisors is an integer number (362882781).

Almost surely, 2^725765561 is an apocalyptic number.

It is an amenable number.

725765561 is a deficient number, since it is larger than the sum of its proper divisors (1).

725765561 is an equidigital number, since it uses as much as digits as its factorization.

725765561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 441000, while the sum is 44.

The square root of 725765561 is about 26940.0363956696. The cubic root of 725765561 is about 898.6669817436. Note that the first 3 decimals are identical.

The spelling of 725765561 in words is "seven hundred twenty-five million, seven hundred sixty-five thousand, five hundred sixty-one".