664873 has 4 divisors (see below), whose sum is σ = 725328. Its totient is φ = 604420.

The previous prime is 664849. The next prime is 664879. The reversal of 664873 is 378466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 664873 - 2¹³ = 656681 is a prime.

It is a super-2 number, since 2×664873² = 884112212258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30211 + ... + 30232.

It is an arithmetic number, because the mean of its divisors is an integer number (181332).

2⁶⁶⁴⁸⁷³ is an apocalyptic number.

It is an amenable number.

664873 is a deficient number, since it is larger than the sum of its proper divisors (60455).

664873 is a wasteful number, since it uses less digits than its factorization.

664873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60454.

The product of its digits is 24192, while the sum is 34.

The square root of 664873 is about 815.3974491007. The cubic root of 664873 is about 87.2796304975.

The spelling of 664873 in words is "six hundred sixty-four thousand, eight hundred seventy-three".