665953 has 2 divisors, whose sum is σ = 665954. Its totient is φ = 665952.

The previous prime is 665947. The next prime is 665981. The reversal of 665953 is 359566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 451584 + 214369 = 672^2 + 463^2 .

It is a cyclic number.

It is not a de Polignac number, because 665953 - 2⁵ = 665921 is a prime.

It is a plaindrome in base 9.

It is not a weakly prime, because it can be changed into another prime (665923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332976 + 332977.

It is an arithmetic number, because the mean of its divisors is an integer number (332977).

2⁶⁶⁵⁹⁵³ is an apocalyptic number.

It is an amenable number.

665953 is a deficient number, since it is larger than the sum of its proper divisors (1).

665953 is an equidigital number, since it uses as much as digits as its factorization.

665953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24300, while the sum is 34.

The square root of 665953 is about 816.0594341100. The cubic root of 665953 is about 87.3268630808.

The spelling of 665953 in words is "six hundred sixty-five thousand, nine hundred fifty-three".