640093 has 4 divisors (see below), whose sum is σ = 653760. Its totient is φ = 626428.

The previous prime is 640069. The next prime is 640099. The reversal of 640093 is 390046.

640093 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 390046 = 2 ⋅195023.

It is a cyclic number.

It is not a de Polignac number, because 640093 - 2⁵ = 640061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640099) 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, 6763 + ... + 6856.

It is an arithmetic number, because the mean of its divisors is an integer number (163440).

2⁶⁴⁰⁰⁹³ is an apocalyptic number.

It is an amenable number.

640093 is a deficient number, since it is larger than the sum of its proper divisors (13667).

640093 is a wasteful number, since it uses less digits than its factorization.

640093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13666.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 640093 is about 800.0581228886. The cubic root of 640093 is about 86.1815616163.

Subtracting from 640093 its reverse (390046), we obtain a cube (250047 = 63³).

The spelling of 640093 in words is "six hundred forty thousand, ninety-three".