664870 has 16 divisors (see below), whose sum is σ = 1267488. Its totient is φ = 250240.

The previous prime is 664849. The next prime is 664879. The reversal of 664870 is 78466.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 1786 + ... + 2125.

It is an arithmetic number, because the mean of its divisors is an integer number (79218).

2⁶⁶⁴⁸⁷⁰ is an apocalyptic number.

664870 is a deficient number, since it is larger than the sum of its proper divisors (602618).

664870 is a wasteful number, since it uses less digits than its factorization.

664870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3935.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 664870 is about 815.3956095050. The cubic root of 664870 is about 87.2794992246.

The spelling of 664870 in words is "six hundred sixty-four thousand, eight hundred seventy".