12367781 has 2 divisors, whose sum is σ = 12367782. Its totient is φ = 12367780.

The previous prime is 12367769. The next prime is 12367783. The reversal of 12367781 is 18776321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10432900 + 1934881 = 3230^2 + 1391^2 .

It is a cyclic number.

It is not a de Polignac number, because 12367781 - 2¹⁸ = 12105637 is a prime.

It is a super-2 number, since 2×12367781² = 305924013727922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 12367783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12367783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6183890 + 6183891.

It is an arithmetic number, because the mean of its divisors is an integer number (6183891).

Almost surely, 2^12367781 is an apocalyptic number.

It is an amenable number.

12367781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12367781 is an equidigital number, since it uses as much as digits as its factorization.

12367781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 35.

The square root of 12367781 is about 3516.7856062035. The cubic root of 12367781 is about 231.2582645208.

The spelling of 12367781 in words is "twelve million, three hundred sixty-seven thousand, seven hundred eighty-one".