21133231220 has 48 divisors (see below), whose sum is σ = 46449583488. Its totient is φ = 8061271680.

The previous prime is 21133231201. The next prime is 21133231241. The reversal of 21133231220 is 2213233112.

It is a super-2 number, since 2×21133231220² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21133231192 and 21133231201.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 82862 + ... + 221658.

It is an arithmetic number, because the mean of its divisors is an integer number (967699656).

Almost surely, 2^21133231220 is an apocalyptic number.

21133231220 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 21133231220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23224791744).

21133231220 is an abundant number, since it is smaller than the sum of its proper divisors (25316352268).

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

21133231220 is a wasteful number, since it uses less digits than its factorization.

21133231220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139160 (or 139158 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21133231220 its reverse (2213233112), we get a palindrome (23346464332).

The spelling of 21133231220 in words is "twenty-one billion, one hundred thirty-three million, two hundred thirty-one thousand, two hundred twenty".