1856643305663 has 2 divisors, whose sum is σ = 1856643305664. Its totient is φ = 1856643305662.

The previous prime is 1856643305653. The next prime is 1856643305689. The reversal of 1856643305663 is 3665033466581.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1856643305663 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1856643305599 and 1856643305608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1856643305653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 928321652831 + 928321652832.

It is an arithmetic number, because the mean of its divisors is an integer number (928321652832).

Almost surely, 2^{1856643305663} is an apocalyptic number.

1856643305663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1856643305663 is an equidigital number, since it uses as much as digits as its factorization.

1856643305663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27993600, while the sum is 56.

The spelling of 1856643305663 in words is "one trillion, eight hundred fifty-six billion, six hundred forty-three million, three hundred five thousand, six hundred sixty-three".