12777315721 has 2 divisors, whose sum is σ = 12777315722. Its totient is φ = 12777315720.

The previous prime is 12777315689. The next prime is 12777315739. The reversal of 12777315721 is 12751377721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12776911225 + 404496 = 113035^2 + 636^2 .

It is a cyclic number.

It is not a de Polignac number, because 12777315721 - 2⁵ = 12777315689 is a prime.

It is a super-2 number, since 2×12777315721² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12777315781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6388657860 + 6388657861.

It is an arithmetic number, because the mean of its divisors is an integer number (6388657861).

Almost surely, 2^12777315721 is an apocalyptic number.

It is an amenable number.

12777315721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12777315721 is an equidigital number, since it uses as much as digits as its factorization.

12777315721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144060, while the sum is 43.

The spelling of 12777315721 in words is "twelve billion, seven hundred seventy-seven million, three hundred fifteen thousand, seven hundred twenty-one".