664212 has 12 divisors (see below), whose sum is σ = 1549856. Its totient is φ = 221400.

The previous prime is 664211. The next prime is 664243. The reversal of 664212 is 212466.

It is a happy number.

664212 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27664 + ... + 27687.

2⁶⁶⁴²¹² is an apocalyptic number.

It is an amenable number.

664212 is an abundant number, since it is smaller than the sum of its proper divisors (885644).

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

664212 is a wasteful number, since it uses less digits than its factorization.

664212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55358 (or 55356 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 664212 is about 814.9920245009. The cubic root of 664212 is about 87.2506971699.

Adding to 664212 its reverse (212466), we get a palindrome (876678).

It can be divided in two parts, 66 and 4212, that added together give a triangular number (4278 = T₉₂).

The spelling of 664212 in words is "six hundred sixty-four thousand, two hundred twelve".