663601 has 2 divisors, whose sum is σ = 663602. Its totient is φ = 663600.

The previous prime is 663599. The next prime is 663631. The reversal of 663601 is 106366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 360000 + 303601 = 600^2 + 551^2 .

It is a cyclic number.

It is not a de Polignac number, because 663601 - 2¹ = 663599 is a prime.

Together with 663599, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (663631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331800 + 331801.

It is an arithmetic number, because the mean of its divisors is an integer number (331801).

2⁶⁶³⁶⁰¹ is an apocalyptic number.

It is an amenable number.

663601 is a deficient number, since it is larger than the sum of its proper divisors (1).

663601 is an equidigital number, since it uses as much as digits as its factorization.

663601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 663601 is about 814.6170879622. The cubic root of 663601 is about 87.2239353675.

Adding to 663601 its reverse (106366), we get a palindrome (769967).

The spelling of 663601 in words is "six hundred sixty-three thousand, six hundred one".