212121200 has 30 divisors (see below), whose sum is σ = 509622144. Its totient is φ = 84848320.

The previous prime is 212121197. The next prime is 212121209. The reversal of 212121200 is 2121212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121209) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 264752 + ... + 265551.

Almost surely, 2^212121200 is an apocalyptic number.

212121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212121200 is an abundant number, since it is smaller than the sum of its proper divisors (297500944).

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

212121200 is a wasteful number, since it uses less digits than its factorization.

212121200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530321 (or 530310 counting only the distinct ones).

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

The square root of 212121200 is about 14564.3812089632. The cubic root of 212121200 is about 596.3868035477.

Adding to 212121200 its reverse (2121212), we get a palindrome (214242412).

Multiplying 212121200 by its reverse (2121212), we get a square (449954034894400 = 21212120²).

212121200 divided by its reverse (2121212) gives a square (100 = 10²).

The spelling of 212121200 in words is "two hundred twelve million, one hundred twenty-one thousand, two hundred".