647663 has 2 divisors, whose sum is σ = 647664. Its totient is φ = 647662.

The previous prime is 647659. The next prime is 647687. The reversal of 647663 is 366746.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 647663 - 2² = 647659 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647693) 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, 323831 + 323832.

It is an arithmetic number, because the mean of its divisors is an integer number (323832).

2⁶⁴⁷⁶⁶³ is an apocalyptic number.

647663 is a deficient number, since it is larger than the sum of its proper divisors (1).

647663 is an equidigital number, since it uses as much as digits as its factorization.

647663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 32.

The square root of 647663 is about 804.7751238700. The cubic root of 647663 is about 86.5199704411.

The spelling of 647663 in words is "six hundred forty-seven thousand, six hundred sixty-three".