12385781 has 2 divisors, whose sum is σ = 12385782. Its totient is φ = 12385780.

The previous prime is 12385757. The next prime is 12385783. The reversal of 12385781 is 18758321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9796900 + 2588881 = 3130^2 + 1609^2 .

It is a cyclic number.

It is not a de Polignac number, because 12385781 - 2⁶ = 12385717 is a prime.

It is a super-2 number, since 2×12385781² = 306815141959922, which contains 22 as substring.

Together with 12385783, 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 (12385783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6192890 + 6192891.

It is an arithmetic number, because the mean of its divisors is an integer number (6192891).

Almost surely, 2^12385781 is an apocalyptic number.

It is an amenable number.

12385781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12385781 is an equidigital number, since it uses as much as digits as its factorization.

12385781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 35.

The square root of 12385781 is about 3519.3438308867. The cubic root of 12385781 is about 231.3704008035.

The spelling of 12385781 in words is "twelve million, three hundred eighty-five thousand, seven hundred eighty-one".