665563 has 2 divisors, whose sum is σ = 665564. Its totient is φ = 665562.

The previous prime is 665557. The next prime is 665569. The reversal of 665563 is 365566.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (665557) and next prime (665569).

It is a cyclic number.

It is not a de Polignac number, because 665563 - 2⁹ = 665051 is a prime.

It is not a weakly prime, because it can be changed into another prime (665569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332781 + 332782.

It is an arithmetic number, because the mean of its divisors is an integer number (332782).

2⁶⁶⁵⁵⁶³ is an apocalyptic number.

665563 is a deficient number, since it is larger than the sum of its proper divisors (1).

665563 is an equidigital number, since it uses as much as digits as its factorization.

665563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 31.

The square root of 665563 is about 815.8204459316. The cubic root of 665563 is about 87.3098127649.

The spelling of 665563 in words is "six hundred sixty-five thousand, five hundred sixty-three".