523731661 has 2 divisors, whose sum is σ = 523731662. Its totient is φ = 523731660.

The previous prime is 523731653. The next prime is 523731671. The reversal of 523731661 is 166137325.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 324216036 + 199515625 = 18006^2 + 14125^2 .

It is a cyclic number.

It is not a de Polignac number, because 523731661 - 2³ = 523731653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (523731671) 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, 261865830 + 261865831.

It is an arithmetic number, because the mean of its divisors is an integer number (261865831).

Almost surely, 2^523731661 is an apocalyptic number.

It is an amenable number.

523731661 is a deficient number, since it is larger than the sum of its proper divisors (1).

523731661 is an equidigital number, since it uses as much as digits as its factorization.

523731661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 34.

The square root of 523731661 is about 22885.1843121265. The cubic root of 523731661 is about 806.0641564646.

Adding to 523731661 its reverse (166137325), we get a palindrome (689868986).

The spelling of 523731661 in words is "five hundred twenty-three million, seven hundred thirty-one thousand, six hundred sixty-one".