21021002222020 has 12 divisors (see below), whose sum is σ = 44144104666284. Its totient is φ = 8408400888800.

The previous prime is 21021002221987. The next prime is 21021002222093. The reversal of 21021002222020 is 2022220012012.

It can be written as a sum of positive squares in 2 ways, for example, as 9073734405696 + 11947267816324 = 3012264^2 + 3456482^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21021002221985 and 21021002222003.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 525525055531 + ... + 525525055570.

It is an arithmetic number, because the mean of its divisors is an integer number (3678675388857).

Almost surely, 2^{21021002222020} is an apocalyptic number.

21021002222020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021002222020 is an abundant number, since it is smaller than the sum of its proper divisors (23123102444264).

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

21021002222020 is a wasteful number, since it uses less digits than its factorization.

21021002222020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051050111110 (or 1051050111108 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21021002222020 its reverse (2022220012012), we get a palindrome (23043222234032).

The spelling of 21021002222020 in words is "twenty-one trillion, twenty-one billion, two million, two hundred twenty-two thousand, twenty".