1866307826249 has 2 divisors, whose sum is σ = 1866307826250. Its totient is φ = 1866307826248.

The previous prime is 1866307826237. The next prime is 1866307826267. The reversal of 1866307826249 is 9426287036681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1854207826249 + 12100000000 = 1361693^2 + 110000^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866307826249 - 2⁴ = 1866307826233 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1866307826191 and 1866307826200.

It is not a weakly prime, because it can be changed into another prime (1866307826549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 933153913124 + 933153913125.

It is an arithmetic number, because the mean of its divisors is an integer number (933153913125).

Almost surely, 2^{1866307826249} is an apocalyptic number.

It is an amenable number.

1866307826249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1866307826249 is an equidigital number, since it uses as much as digits as its factorization.

1866307826249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41803776, while the sum is 62.

The spelling of 1866307826249 in words is "one trillion, eight hundred sixty-six billion, three hundred seven million, eight hundred twenty-six thousand, two hundred forty-nine".