664663 has 2 divisors, whose sum is σ = 664664. Its totient is φ = 664662.

The previous prime is 664661. The next prime is 664667. The reversal of 664663 is 366466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664663 - 2¹ = 664661 is a prime.

Together with 664661, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332331 + 332332.

It is an arithmetic number, because the mean of its divisors is an integer number (332332).

2⁶⁶⁴⁶⁶³ is an apocalyptic number.

664663 is a deficient number, since it is larger than the sum of its proper divisors (1).

664663 is an equidigital number, since it uses as much as digits as its factorization.

664663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 31.

The square root of 664663 is about 815.2686673729. The cubic root of 664663 is about 87.2704404454.

The spelling of 664663 in words is "six hundred sixty-four thousand, six hundred sixty-three".