13256756087521 has 2 divisors, whose sum is σ = 13256756087522. Its totient is φ = 13256756087520.

The previous prime is 13256756087483. The next prime is 13256756087543. The reversal of 13256756087521 is 12578065765231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13067060995921 + 189695091600 = 3614839^2 + 435540^2 .

It is a cyclic number.

It is not a de Polignac number, because 13256756087521 - 2⁴¹ = 11057732831969 is a prime.

It is not a weakly prime, because it can be changed into another prime (13256756087581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6628378043760 + 6628378043761.

It is an arithmetic number, because the mean of its divisors is an integer number (6628378043761).

Almost surely, 2^{13256756087521} is an apocalyptic number.

It is an amenable number.

13256756087521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13256756087521 is an equidigital number, since it uses as much as digits as its factorization.

13256756087521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168000, while the sum is 58.

The spelling of 13256756087521 in words is "thirteen trillion, two hundred fifty-six billion, seven hundred fifty-six million, eighty-seven thousand, five hundred twenty-one".