21001222201020 has 48 divisors (see below), whose sum is σ = 58803651533088. Its totient is φ = 5600304075520.

The previous prime is 21001222201019. The next prime is 21001222201033. The reversal of 21001222201020 is 2010222210012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20013010 + ... + 21036230.

It is an arithmetic number, because the mean of its divisors is an integer number (1225076073606).

Almost surely, 2^{21001222201020} is an apocalyptic number.

21001222201020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001222201020 is an abundant number, since it is smaller than the sum of its proper divisors (37802429332068).

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

21001222201020 is a wasteful number, since it uses less digits than its factorization.

21001222201020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1365310 (or 1365308 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21001222201020 its reverse (2010222210012), we get a palindrome (23011444411032).

The spelling of 21001222201020 in words is "twenty-one trillion, one billion, two hundred twenty-two million, two hundred one thousand, twenty".