640212 has 24 divisors (see below), whose sum is σ = 1542912. Its totient is φ = 206400.

The previous prime is 640193. The next prime is 640219. The reversal of 640212 is 212046.

It is a junction number, because it is equal to n+sod(n) for n = 640191 and 640200.

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 640212.

It is not an unprimeable number, because it can be changed into a prime (640219) by changing a digit.

640212 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 489 + ... + 1232.

It is an arithmetic number, because the mean of its divisors is an integer number (64288).

2⁶⁴⁰²¹² is an apocalyptic number.

640212 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

640212 is an abundant number, since it is smaller than the sum of its proper divisors (902700).

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

640212 is a wasteful number, since it uses less digits than its factorization.

640212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759 (or 1757 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 640212 is about 800.1324890292. The cubic root of 640212 is about 86.1869019707.

Adding to 640212 its reverse (212046), we get a palindrome (852258).

The spelling of 640212 in words is "six hundred forty thousand, two hundred twelve".