13666356497 has 2 divisors, whose sum is σ = 13666356498. Its totient is φ = 13666356496.

The previous prime is 13666356469. The next prime is 13666356511. The reversal of 13666356497 is 79465366631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12750023056 + 916333441 = 112916^2 + 30271^2 .

It is a cyclic number.

It is not a de Polignac number, because 13666356497 - 2⁸ = 13666356241 is a prime.

It is a super-2 number, since 2×13666356497² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13666356467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6833178248 + 6833178249.

It is an arithmetic number, because the mean of its divisors is an integer number (6833178249).

Almost surely, 2^13666356497 is an apocalyptic number.

It is an amenable number.

13666356497 is a deficient number, since it is larger than the sum of its proper divisors (1).

13666356497 is an equidigital number, since it uses as much as digits as its factorization.

13666356497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14696640, while the sum is 56.

The spelling of 13666356497 in words is "thirteen billion, six hundred sixty-six million, three hundred fifty-six thousand, four hundred ninety-seven".