12543975557 has 2 divisors, whose sum is σ = 12543975558. Its totient is φ = 12543975556.

The previous prime is 12543975533. The next prime is 12543975569. The reversal of 12543975557 is 75557934521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7465132801 + 5078842756 = 86401^2 + 71266^2 .

It is an emirp because it is prime and its reverse (75557934521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12543975557 - 2¹⁴ = 12543959173 is a prime.

It is a super-2 number, since 2×12543975557² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12543975499 and 12543975508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12543975757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6271987778 + 6271987779.

It is an arithmetic number, because the mean of its divisors is an integer number (6271987779).

Almost surely, 2^12543975557 is an apocalyptic number.

It is an amenable number.

12543975557 is a deficient number, since it is larger than the sum of its proper divisors (1).

12543975557 is an equidigital number, since it uses as much as digits as its factorization.

12543975557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6615000, while the sum is 53.

The spelling of 12543975557 in words is "twelve billion, five hundred forty-three million, nine hundred seventy-five thousand, five hundred fifty-seven".