12775541855821 has 2 divisors, whose sum is σ = 12775541855822. Its totient is φ = 12775541855820.

The previous prime is 12775541855773. The next prime is 12775541855837. The reversal of 12775541855821 is 12855814557721.

12775541855821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6759927200196 + 6015614655625 = 2599986^2 + 2452675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12775541855821 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12775541855821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12775541855861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6387770927910 + 6387770927911.

It is an arithmetic number, because the mean of its divisors is an integer number (6387770927911).

Almost surely, 2^{12775541855821} is an apocalyptic number.

It is an amenable number.

12775541855821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12775541855821 is an equidigital number, since it uses as much as digits as its factorization.

12775541855821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31360000, while the sum is 61.

The spelling of 12775541855821 in words is "twelve trillion, seven hundred seventy-five billion, five hundred forty-one million, eight hundred fifty-five thousand, eight hundred twenty-one".