21021120102020 has 12 divisors (see below), whose sum is σ = 44144352214284. Its totient is φ = 8408448040800.

The previous prime is 21021120102019. The next prime is 21021120102061. The reversal of 21021120102020 is 2020102112012.

It can be written as a sum of positive squares in 2 ways, for example, as 11862362095684 + 9158758006336 = 3444178^2 + 3026344^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21021120101986 and 21021120102004.

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, 525528002531 + ... + 525528002570.

It is an arithmetic number, because the mean of its divisors is an integer number (3678696017857).

Almost surely, 2^{21021120102020} is an apocalyptic number.

21021120102020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021120102020 is an abundant number, since it is smaller than the sum of its proper divisors (23123232112264).

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

21021120102020 is a wasteful number, since it uses less digits than its factorization.

21021120102020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051056005110 (or 1051056005108 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21021120102020 its reverse (2020102112012), we get a palindrome (23041222214032).

The spelling of 21021120102020 in words is "twenty-one trillion, twenty-one billion, one hundred twenty million, one hundred two thousand, twenty".