640590 has 32 divisors (see below), whose sum is σ = 1558656. Its totient is φ = 168480.

The previous prime is 640589. The next prime is 640613. The reversal of 640590 is 95046.

640590 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 640590.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3849 + ... + 4011.

It is an arithmetic number, because the mean of its divisors is an integer number (48708).

2⁶⁴⁰⁵⁹⁰ is an apocalyptic number.

640590 is an abundant number, since it is smaller than the sum of its proper divisors (918066).

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

640590 is a wasteful number, since it uses less digits than its factorization.

640590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 640590 is about 800.3686650538. The cubic root of 640590 is about 86.2038610609.

The spelling of 640590 in words is "six hundred forty thousand, five hundred ninety".