21212021200 has 60 divisors (see below), whose sum is σ = 52046222400. Its totient is φ = 8304273280.

The previous prime is 21212021161. The next prime is 21212021221. The reversal of 21212021200 is 212021212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 545350 + ... + 582949.

It is an arithmetic number, because the mean of its divisors is an integer number (867437040).

Almost surely, 2^21212021200 is an apocalyptic number.

21212021200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212021200 is an abundant number, since it is smaller than the sum of its proper divisors (30834201200).

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

21212021200 is a wasteful number, since it uses less digits than its factorization.

21212021200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128364 (or 1128353 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21212021200 its reverse (212021212), we get a palindrome (21424042412).

The spelling of 21212021200 in words is "twenty-one billion, two hundred twelve million, twenty-one thousand, two hundred".