212216664 has 128 divisors (see below), whose sum is σ = 611193600. Its totient is φ = 60802560.

The previous prime is 212216659. The next prime is 212216723. The reversal of 212216664 is 466612212.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 405507 + ... + 406029.

It is an arithmetic number, because the mean of its divisors is an integer number (4774950).

Almost surely, 2^212216664 is an apocalyptic number.

212216664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212216664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305596800).

212216664 is an abundant number, since it is smaller than the sum of its proper divisors (398976936).

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

212216664 is a wasteful number, since it uses less digits than its factorization.

212216664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625 (or 621 counting only the distinct ones).

The product of its digits is 6912, while the sum is 30.

The square root of 212216664 is about 14567.6581508491. The cubic root of 212216664 is about 596.4762570159.

Adding to 212216664 its reverse (466612212), we get a palindrome (678828876).

The spelling of 212216664 in words is "two hundred twelve million, two hundred sixteen thousand, six hundred sixty-four".