2806640206861 has 2 divisors, whose sum is σ = 2806640206862. Its totient is φ = 2806640206860.

The previous prime is 2806640206819. The next prime is 2806640206871. The reversal of 2806640206861 is 1686020466082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2648658600900 + 157981605961 = 1627470^2 + 397469^2 .

It is a cyclic number.

It is not a de Polignac number, because 2806640206861 - 2¹¹ = 2806640204813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2806640206871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1403320103430 + 1403320103431.

It is an arithmetic number, because the mean of its divisors is an integer number (1403320103431).

Almost surely, 2^{2806640206861} is an apocalyptic number.

It is an amenable number.

2806640206861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2806640206861 is an equidigital number, since it uses as much as digits as its factorization.

2806640206861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1327104, while the sum is 49.

The spelling of 2806640206861 in words is "two trillion, eight hundred six billion, six hundred forty million, two hundred six thousand, eight hundred sixty-one".