640622 has 16 divisors (see below), whose sum is σ = 1004400. Its totient is φ = 306240.

The previous prime is 640621. The next prime is 640631. The reversal of 640622 is 226046.

It is a junction number, because it is equal to n+sod(n) for n = 640594 and 640603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7154 + ... + 7242.

It is an arithmetic number, because the mean of its divisors is an integer number (62775).

2⁶⁴⁰⁶²² is an apocalyptic number.

640622 is a deficient number, since it is larger than the sum of its proper divisors (363778).

640622 is a wasteful number, since it uses less digits than its factorization.

640622 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 640622 is about 800.3886555918. The cubic root of 640622 is about 86.2052964448.

Subtracting from 640622 its product of nonzero digits (576), we obtain a palindrome (640046).

Adding to 640622 its reverse (226046), we get a palindrome (866668).

The spelling of 640622 in words is "six hundred forty thousand, six hundred twenty-two".