664775 has 6 divisors (see below), whose sum is σ = 824352. Its totient is φ = 531800.

The previous prime is 664771. The next prime is 664777. The reversal of 664775 is 577466.

664775 = T₂₁₈ + T₂₁₉ + ... + T₂₄₂.

It is not a de Polignac number, because 664775 - 2² = 664771 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664771) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13271 + ... + 13320.

It is an arithmetic number, because the mean of its divisors is an integer number (137392).

2⁶⁶⁴⁷⁷⁵ is an apocalyptic number.

664775 is a deficient number, since it is larger than the sum of its proper divisors (159577).

664775 is a wasteful number, since it uses less digits than its factorization.

664775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26601 (or 26596 counting only the distinct ones).

The product of its digits is 35280, while the sum is 35.

The square root of 664775 is about 815.3373534924. The cubic root of 664775 is about 87.2753420473.

The spelling of 664775 in words is "six hundred sixty-four thousand, seven hundred seventy-five".