664240 has 60 divisors (see below), whose sum is σ = 1700784. Its totient is φ = 240768.

The previous prime is 664211. The next prime is 664243. The reversal of 664240 is 42466.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (664243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28869 + ... + 28891.

2⁶⁶⁴²⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (850392).

664240 is an abundant number, since it is smaller than the sum of its proper divisors (1036544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664240 is a wasteful number, since it uses less digits than its factorization.

664240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 664240 is about 815.0092024020. The cubic root of 664240 is about 87.2519231766.

It can be divided in two parts, 6 and 64240, that added together give a palindrome (64246).

The spelling of 664240 in words is "six hundred sixty-four thousand, two hundred forty".