21221222011002 has 96 divisors (see below), whose sum is σ = 51118519495680. Its totient is φ = 6318351406080.

The previous prime is 21221222011001. The next prime is 21221222011021. The reversal of 21221222011002 is 20011022212212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21221222011001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 76238443 + ... + 76516289.

It is an arithmetic number, because the mean of its divisors is an integer number (532484578080).

Almost surely, 2^{21221222011002} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221222011002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25559259747840).

21221222011002 is an abundant number, since it is smaller than the sum of its proper divisors (29897297484678).

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

21221222011002 is a wasteful number, since it uses less digits than its factorization.

21221222011002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288428 (or 288425 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21221222011002 its reverse (20011022212212), we get a palindrome (41232244223214).

The spelling of 21221222011002 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, eleven thousand, two".