13123356661 has 2 divisors, whose sum is σ = 13123356662. Its totient is φ = 13123356660.

The previous prime is 13123356647. The next prime is 13123356671. The reversal of 13123356661 is 16665332131.

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., 7195280625 + 5928076036 = 84825^2 + 76994^2 .

It is a cyclic number.

It is not a de Polignac number, because 13123356661 - 2¹⁷ = 13123225589 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13123356661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13123356671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6561678330 + 6561678331.

It is an arithmetic number, because the mean of its divisors is an integer number (6561678331).

Almost surely, 2^13123356661 is an apocalyptic number.

It is an amenable number.

13123356661 is a deficient number, since it is larger than the sum of its proper divisors (1).

13123356661 is an equidigital number, since it uses as much as digits as its factorization.

13123356661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 37.

Adding to 13123356661 its reverse (16665332131), we get a palindrome (29788688792).

The spelling of 13123356661 in words is "thirteen billion, one hundred twenty-three million, three hundred fifty-six thousand, six hundred sixty-one".