531243520261 has 2 divisors, whose sum is σ = 531243520262. Its totient is φ = 531243520260.

The previous prime is 531243520201. The next prime is 531243520267. The reversal of 531243520261 is 162025342135.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 501695973025 + 29547547236 = 708305^2 + 171894^2 .

It is a cyclic number.

It is not a de Polignac number, because 531243520261 - 2¹⁵ = 531243487493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531243520267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265621760130 + 265621760131.

It is an arithmetic number, because the mean of its divisors is an integer number (265621760131).

Almost surely, 2^531243520261 is an apocalyptic number.

It is an amenable number.

531243520261 is a deficient number, since it is larger than the sum of its proper divisors (1).

531243520261 is an equidigital number, since it uses as much as digits as its factorization.

531243520261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 34.

Adding to 531243520261 its reverse (162025342135), we get a palindrome (693268862396).

The spelling of 531243520261 in words is "five hundred thirty-one billion, two hundred forty-three million, five hundred twenty thousand, two hundred sixty-one".