12771565777 has 2 divisors, whose sum is σ = 12771565778. Its totient is φ = 12771565776.

The previous prime is 12771565759. The next prime is 12771565799. The reversal of 12771565777 is 77756517721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10591703056 + 2179862721 = 102916^2 + 46689^2 .

It is a cyclic number.

It is not a de Polignac number, because 12771565777 - 2¹¹ = 12771563729 is a prime.

It is a super-2 number, since 2×12771565777² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12771565717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6385782888 + 6385782889.

It is an arithmetic number, because the mean of its divisors is an integer number (6385782889).

Almost surely, 2^12771565777 is an apocalyptic number.

It is an amenable number.

12771565777 is a deficient number, since it is larger than the sum of its proper divisors (1).

12771565777 is an equidigital number, since it uses as much as digits as its factorization.

12771565777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5042100, while the sum is 55.

The spelling of 12771565777 in words is "twelve billion, seven hundred seventy-one million, five hundred sixty-five thousand, seven hundred seventy-seven".