12757781 has 2 divisors, whose sum is σ = 12757782. Its totient is φ = 12757780.

The previous prime is 12757753. The next prime is 12757807. The reversal of 12757781 is 18775721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9394225 + 3363556 = 3065^2 + 1834^2 .

It is an emirp because it is prime and its reverse (18775721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12757781 - 2¹⁴ = 12741397 is a prime.

It is a super-2 number, since 2×12757781² = 325521952087922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12757741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6378890 + 6378891.

It is an arithmetic number, because the mean of its divisors is an integer number (6378891).

Almost surely, 2^12757781 is an apocalyptic number.

It is an amenable number.

12757781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12757781 is an equidigital number, since it uses as much as digits as its factorization.

12757781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27440, while the sum is 38.

The square root of 12757781 is about 3571.8036060232. The cubic root of 12757781 is about 233.6639501390.

The spelling of 12757781 in words is "twelve million, seven hundred fifty-seven thousand, seven hundred eighty-one".