664489 has 12 divisors (see below), whose sum is σ = 787968. Its totient is φ = 558600.

The previous prime is 664471. The next prime is 664507. The reversal of 664489 is 984466.

It is an interprime number because it is at equal distance from previous prime (664471) and next prime (664507).

It is not a de Polignac number, because 664489 - 2⁹ = 663977 is a prime.

It is a super-2 number, since 2×664489² = 883091262242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664459) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3384 + ... + 3574.

It is an arithmetic number, because the mean of its divisors is an integer number (65664).

2⁶⁶⁴⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

664489 is a deficient number, since it is larger than the sum of its proper divisors (123479).

664489 is a wasteful number, since it uses less digits than its factorization.

664489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 269 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 664489 is about 815.1619471001. The cubic root of 664489 is about 87.2628243643.

The spelling of 664489 in words is "six hundred sixty-four thousand, four hundred eighty-nine".