12945781 has 2 divisors, whose sum is σ = 12945782. Its totient is φ = 12945780.

The previous prime is 12945769. The next prime is 12945787. The reversal of 12945781 is 18754921.

12945781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12320100 + 625681 = 3510^2 + 791^2 .

It is a cyclic number.

It is not a de Polignac number, because 12945781 - 2¹⁷ = 12814709 is a prime.

It is a super-2 number, since 2×12945781² = 335186491399922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12945781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12945787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6472890 + 6472891.

It is an arithmetic number, because the mean of its divisors is an integer number (6472891).

Almost surely, 2^12945781 is an apocalyptic number.

It is an amenable number.

12945781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12945781 is an equidigital number, since it uses as much as digits as its factorization.

12945781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 12945781 is about 3598.0245969143. The cubic root of 12945781 is about 234.8061234808.

The spelling of 12945781 in words is "twelve million, nine hundred forty-five thousand, seven hundred eighty-one".