665573 has 2 divisors, whose sum is σ = 665574. Its totient is φ = 665572.

The previous prime is 665569. The next prime is 665591. The reversal of 665573 is 375566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 588289 + 77284 = 767^2 + 278^2 .

It is a cyclic number.

It is not a de Polignac number, because 665573 - 2² = 665569 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332786 + 332787.

It is an arithmetic number, because the mean of its divisors is an integer number (332787).

2⁶⁶⁵⁵⁷³ is an apocalyptic number.

It is an amenable number.

665573 is a deficient number, since it is larger than the sum of its proper divisors (1).

665573 is an equidigital number, since it uses as much as digits as its factorization.

665573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18900, while the sum is 32.

The square root of 665573 is about 815.8265747081. The cubic root of 665573 is about 87.3102500357.

The spelling of 665573 in words is "six hundred sixty-five thousand, five hundred seventy-three".