861212771 has 2 divisors, whose sum is σ = 861212772. Its totient is φ = 861212770.

The previous prime is 861212743. The next prime is 861212801. The reversal of 861212771 is 177212168.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 861212771 - 2¹⁸ = 860950627 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (861212711) 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, 430606385 + 430606386.

It is an arithmetic number, because the mean of its divisors is an integer number (430606386).

Almost surely, 2^861212771 is an apocalyptic number.

861212771 is a deficient number, since it is larger than the sum of its proper divisors (1).

861212771 is an equidigital number, since it uses as much as digits as its factorization.

861212771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9408, while the sum is 35.

The square root of 861212771 is about 29346.4268864201. The cubic root of 861212771 is about 951.4153495858.

The spelling of 861212771 in words is "eight hundred sixty-one million, two hundred twelve thousand, seven hundred seventy-one".