13043681557 has 2 divisors, whose sum is σ = 13043681558. Its totient is φ = 13043681556.

The previous prime is 13043681479. The next prime is 13043681587. The reversal of 13043681557 is 75518634031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10223434321 + 2820247236 = 101111^2 + 53106^2 .

It is a cyclic number.

It is not a de Polignac number, because 13043681557 - 2²⁷ = 12909463829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13043681587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6521840778 + 6521840779.

It is an arithmetic number, because the mean of its divisors is an integer number (6521840779).

Almost surely, 2^13043681557 is an apocalyptic number.

It is an amenable number.

13043681557 is a deficient number, since it is larger than the sum of its proper divisors (1).

13043681557 is an equidigital number, since it uses as much as digits as its factorization.

13043681557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 302400, while the sum is 43.

The spelling of 13043681557 in words is "thirteen billion, forty-three million, six hundred eighty-one thousand, five hundred fifty-seven".