640488 has 16 divisors (see below), whose sum is σ = 1601280. Its totient is φ = 213488.

The previous prime is 640483. The next prime is 640499. The reversal of 640488 is 884046.

640488 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (640483) by changing a digit.

640488 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13320 + ... + 13367.

It is an arithmetic number, because the mean of its divisors is an integer number (100080).

2⁶⁴⁰⁴⁸⁸ is an apocalyptic number.

It is an amenable number.

640488 is an abundant number, since it is smaller than the sum of its proper divisors (960792).

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

640488 is a wasteful number, since it uses less digits than its factorization.

640488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26696 (or 26692 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 640488 is about 800.3049418815. The cubic root of 640488 is about 86.1992854559.

It can be divided in two parts, 640 and 488, that added together give a triangular number (1128 = T₄₇).

The spelling of 640488 in words is "six hundred forty thousand, four hundred eighty-eight".