856444663 has 2 divisors, whose sum is σ = 856444664. Its totient is φ = 856444662.

The previous prime is 856444651. The next prime is 856444681. The reversal of 856444663 is 366444658.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 856444663 - 2⁹ = 856444151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856444163) 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, 428222331 + 428222332.

It is an arithmetic number, because the mean of its divisors is an integer number (428222332).

Almost surely, 2^856444663 is an apocalyptic number.

856444663 is a deficient number, since it is larger than the sum of its proper divisors (1).

856444663 is an equidigital number, since it uses as much as digits as its factorization.

856444663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1658880, while the sum is 46.

The square root of 856444663 is about 29265.0758242653. The cubic root of 856444663 is about 949.6562608659.

The spelling of 856444663 in words is "eight hundred fifty-six million, four hundred forty-four thousand, six hundred sixty-three".