640022 has 4 divisors (see below), whose sum is σ = 960036. Its totient is φ = 320010.

The previous prime is 640019. The next prime is 640027. The reversal of 640022 is 220046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 220046 = 2 ⋅110023.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 639979 and 640006.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640022.

It is not an unprimeable number, because it can be changed into a prime (640027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160004 + ... + 160007.

It is an arithmetic number, because the mean of its divisors is an integer number (240009).

2⁶⁴⁰⁰²² is an apocalyptic number.

640022 is a deficient number, since it is larger than the sum of its proper divisors (320014).

640022 is a wasteful number, since it uses less digits than its factorization.

640022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320013.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 640022 is about 800.0137498818. The cubic root of 640022 is about 86.1783750392.

Adding to 640022 its reverse (220046), we get a palindrome (860068).

The spelling of 640022 in words is "six hundred forty thousand, twenty-two".