12536842558921 has 2 divisors, whose sum is σ = 12536842558922. Its totient is φ = 12536842558920.

The previous prime is 12536842558873. The next prime is 12536842558937. The reversal of 12536842558921 is 12985524863521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11605162023225 + 931680535696 = 3406635^2 + 965236^2 .

It is a cyclic number.

It is not a de Polignac number, because 12536842558921 - 2²³ = 12536834170313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12536842558921.

It is not a weakly prime, because it can be changed into another prime (12536842558951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6268421279460 + 6268421279461.

It is an arithmetic number, because the mean of its divisors is an integer number (6268421279461).

Almost surely, 2^{12536842558921} is an apocalyptic number.

It is an amenable number.

12536842558921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12536842558921 is an equidigital number, since it uses as much as digits as its factorization.

12536842558921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472000, while the sum is 61.

The spelling of 12536842558921 in words is "twelve trillion, five hundred thirty-six billion, eight hundred forty-two million, five hundred fifty-eight thousand, nine hundred twenty-one".