864418781 has 2 divisors, whose sum is σ = 864418782. Its totient is φ = 864418780.

The previous prime is 864418777. The next prime is 864418843. The reversal of 864418781 is 187814468.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 613354756 + 251064025 = 24766^2 + 15845^2 .

It is a cyclic number.

It is not a de Polignac number, because 864418781 - 2² = 864418777 is a prime.

It is a super-2 number, since 2×864418781² = 1494439657891051922, which contains 22 as substring.

It is a Sophie Germain prime.

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 (864418081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432209390 + 432209391.

It is an arithmetic number, because the mean of its divisors is an integer number (432209391).

Almost surely, 2^864418781 is an apocalyptic number.

It is an amenable number.

864418781 is a deficient number, since it is larger than the sum of its proper divisors (1).

864418781 is an equidigital number, since it uses as much as digits as its factorization.

864418781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 344064, while the sum is 47.

The square root of 864418781 is about 29400.9996598755. Note that the first 3 decimals coincide. The cubic root of 864418781 is about 952.5944890567.

The spelling of 864418781 in words is "eight hundred sixty-four million, four hundred eighteen thousand, seven hundred eighty-one".