640480 has 24 divisors (see below), whose sum is σ = 1513512. Its totient is φ = 256128.

The previous prime is 640477. The next prime is 640483. The reversal of 640480 is 84046.

It is an interprime number because it is at equal distance from previous prime (640477) and next prime (640483).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640483) 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, 1842 + ... + 2161.

It is an arithmetic number, because the mean of its divisors is an integer number (63063).

2⁶⁴⁰⁴⁸⁰ is an apocalyptic number.

It is an amenable number.

640480 is an abundant number, since it is smaller than the sum of its proper divisors (873032).

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

640480 is a wasteful number, since it uses less digits than its factorization.

640480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018 (or 4010 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 640480 is about 800.2999437711. The cubic root of 640480 is about 86.1989265643.

The spelling of 640480 in words is "six hundred forty thousand, four hundred eighty".