11431321261 has 2 divisors, whose sum is σ = 11431321262. Its totient is φ = 11431321260.

The previous prime is 11431321211. The next prime is 11431321277. The reversal of 11431321261 is 16212313411.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10076345161 + 1354976100 = 100381^2 + 36810^2 .

It is a cyclic number.

It is not a de Polignac number, because 11431321261 - 2⁹ = 11431320749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11431321201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5715660630 + 5715660631.

It is an arithmetic number, because the mean of its divisors is an integer number (5715660631).

Almost surely, 2^11431321261 is an apocalyptic number.

It is an amenable number.

11431321261 is a deficient number, since it is larger than the sum of its proper divisors (1).

11431321261 is an equidigital number, since it uses as much as digits as its factorization.

11431321261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

Adding to 11431321261 its reverse (16212313411), we get a palindrome (27643634672).

The spelling of 11431321261 in words is "eleven billion, four hundred thirty-one million, three hundred twenty-one thousand, two hundred sixty-one".