21201222011020 has 24 divisors (see below), whose sum is σ = 44558970662304. Its totient is φ = 8473554625536.

The previous prime is 21201222011003. The next prime is 21201222011041. The reversal of 21201222011020 is 2011022210212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21201222010985 and 21201222011003.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 433361109 + ... + 433410028.

It is an arithmetic number, because the mean of its divisors is an integer number (1856623777596).

Almost surely, 2^{21201222011020} is an apocalyptic number.

21201222011020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201222011020 is an abundant number, since it is smaller than the sum of its proper divisors (23357748651284).

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

21201222011020 is a wasteful number, since it uses less digits than its factorization.

21201222011020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866772369 (or 866772367 counting only the distinct ones).

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

Adding to 21201222011020 its reverse (2011022210212), we get a palindrome (23212244221232).

The spelling of 21201222011020 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, eleven thousand, twenty".