12631781 has 2 divisors, whose sum is σ = 12631782. Its totient is φ = 12631780.

The previous prime is 12631777. The next prime is 12631783. The reversal of 12631781 is 18713621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10023556 + 2608225 = 3166^2 + 1615^2 .

It is a cyclic number.

It is not a de Polignac number, because 12631781 - 2² = 12631777 is a prime.

It is a super-2 number, since 2×12631781² = 319123782463922, which contains 22 as substring.

Together with 12631783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12631783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6315890 + 6315891.

It is an arithmetic number, because the mean of its divisors is an integer number (6315891).

Almost surely, 2^12631781 is an apocalyptic number.

It is an amenable number.

12631781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12631781 is an equidigital number, since it uses as much as digits as its factorization.

12631781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 29.

The square root of 12631781 is about 3554.1216917827. The cubic root of 12631781 is about 232.8921566170.

The spelling of 12631781 in words is "twelve million, six hundred thirty-one thousand, seven hundred eighty-one".