212221100 has 72 divisors (see below), whose sum is σ = 566817888. Its totient is φ = 67161600.

The previous prime is 212221067. The next prime is 212221153. The reversal of 212221100 is 1122212.

It is a happy number.

212221100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2561 + ... + 20760.

Almost surely, 2^212221100 is an apocalyptic number.

212221100 is a gapful number since it is divisible by the number (20) 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 212221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (283408944).

212221100 is an abundant number, since it is smaller than the sum of its proper divisors (354596788).

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

212221100 is a wasteful number, since it uses less digits than its factorization.

212221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23355 (or 23348 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 212221100 is about 14567.8104051364. The cubic root of 212221100 is about 596.4804130675.

Adding to 212221100 its reverse (1122212), we get a palindrome (213343312).

It can be divided in two parts, 21222 and 1100, that added together give a palindrome (22322).

The spelling of 212221100 in words is "two hundred twelve million, two hundred twenty-one thousand, one hundred".