21020221200 has 480 divisors, whose sum is σ = 78287703552. Its totient is φ = 4764672000.

The previous prime is 21020221153. The next prime is 21020221259. The reversal of 21020221200 is 212202012.

It is a super-3 number, since 3×21020221200³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 63505035 + ... + 63505365.

Almost surely, 2^21020221200 is an apocalyptic number.

21020221200 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 21020221200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39143851776).

21020221200 is an abundant number, since it is smaller than the sum of its proper divisors (57267482352).

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

21020221200 is a wasteful number, since it uses less digits than its factorization.

21020221200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663 (or 652 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21020221200 its reverse (212202012), we get a palindrome (21232423212).

The spelling of 21020221200 in words is "twenty-one billion, twenty million, two hundred twenty-one thousand, two hundred".