723539561 has 2 divisors, whose sum is σ = 723539562. Its totient is φ = 723539560.

The previous prime is 723539539. The next prime is 723539569. The reversal of 723539561 is 165935327.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631014400 + 92525161 = 25120^2 + 9619^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-723539561 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (723539569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361769780 + 361769781.

It is an arithmetic number, because the mean of its divisors is an integer number (361769781).

Almost surely, 2^723539561 is an apocalyptic number.

It is an amenable number.

723539561 is a deficient number, since it is larger than the sum of its proper divisors (1).

723539561 is an equidigital number, since it uses as much as digits as its factorization.

723539561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 170100, while the sum is 41.

The square root of 723539561 is about 26898.6906930430. The cubic root of 723539561 is about 897.7472718167.

The spelling of 723539561 in words is "seven hundred twenty-three million, five hundred thirty-nine thousand, five hundred sixty-one".