855687643 has 2 divisors, whose sum is σ = 855687644. Its totient is φ = 855687642.

The previous prime is 855687559. The next prime is 855687647. The reversal of 855687643 is 346786558.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-855687643 is a prime.

It is not a weakly prime, because it can be changed into another prime (855687647) 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, 427843821 + 427843822.

It is an arithmetic number, because the mean of its divisors is an integer number (427843822).

Almost surely, 2^855687643 is an apocalyptic number.

855687643 is a deficient number, since it is larger than the sum of its proper divisors (1).

855687643 is an equidigital number, since it uses as much as digits as its factorization.

855687643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4838400, while the sum is 52.

The square root of 855687643 is about 29252.1391183619. The cubic root of 855687643 is about 949.3763748306.

The spelling of 855687643 in words is "eight hundred fifty-five million, six hundred eighty-seven thousand, six hundred forty-three".