21203331220 has 48 divisors (see below), whose sum is σ = 45704590848. Its totient is φ = 8257859840.

The previous prime is 21203331211. The next prime is 21203331221. The reversal of 21203331220 is 2213330212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203331221) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 386757 + ... + 438163.

It is an arithmetic number, because the mean of its divisors is an integer number (952178976).

Almost surely, 2^21203331220 is an apocalyptic number.

21203331220 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 21203331220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22852295424).

21203331220 is an abundant number, since it is smaller than the sum of its proper divisors (24501259628).

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

21203331220 is a wasteful number, since it uses less digits than its factorization.

21203331220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51960 (or 51958 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21203331220 its reverse (2213330212), we get a palindrome (23416661432).

It can be divided in two parts, 212033 and 31220, that added together give a triangular number (243253 = T₆₉₇).

The spelling of 21203331220 in words is "twenty-one billion, two hundred three million, three hundred thirty-one thousand, two hundred twenty".