21021222112 has 96 divisors (see below), whose sum is σ = 47169410400. Its totient is φ = 9133824000.

The previous prime is 21021222077. The next prime is 21021222119. The reversal of 21021222112 is 21122212012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021222119) 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, 1020814 + ... + 1041202.

It is an arithmetic number, because the mean of its divisors is an integer number (491348025).

Almost surely, 2^21021222112 is an apocalyptic number.

21021222112 is a gapful number since it is divisible by the number (22) 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 21021222112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23584705200).

21021222112 is an abundant number, since it is smaller than the sum of its proper divisors (26148188288).

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

21021222112 is a wasteful number, since it uses less digits than its factorization.

21021222112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20540 (or 20532 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21021222112 its reverse (21122212012), we get a palindrome (42143434124).

It can be divided in two parts, 210212 and 22112, that added together give a square (232324 = 482²).

The spelling of 21021222112 in words is "twenty-one billion, twenty-one million, two hundred twenty-two thousand, one hundred twelve".