13531643557 has 2 divisors, whose sum is σ = 13531643558. Its totient is φ = 13531643556.

The previous prime is 13531643539. The next prime is 13531643581. The reversal of 13531643557 is 75534613531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11423548161 + 2108095396 = 106881^2 + 45914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13531643557 is a prime.

It is a super-2 number, since 2×13531643557² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13531643507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6765821778 + 6765821779.

It is an arithmetic number, because the mean of its divisors is an integer number (6765821779).

Almost surely, 2^13531643557 is an apocalyptic number.

It is an amenable number.

13531643557 is a deficient number, since it is larger than the sum of its proper divisors (1).

13531643557 is an equidigital number, since it uses as much as digits as its factorization.

13531643557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 567000, while the sum is 43.

The spelling of 13531643557 in words is "thirteen billion, five hundred thirty-one million, six hundred forty-three thousand, five hundred fifty-seven".