21120020101020 has 96 divisors (see below), whose sum is σ = 59194204796160. Its totient is φ = 5626469882880.

The previous prime is 21120020100989. The next prime is 21120020101021. The reversal of 21120020101020 is 2010102002112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21120020100987 and 21120020101005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120020101021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 290516836 + ... + 290589524.

It is an arithmetic number, because the mean of its divisors is an integer number (616606299960).

Almost surely, 2^{21120020101020} is an apocalyptic number.

21120020101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120020101020 is an abundant number, since it is smaller than the sum of its proper divisors (38074184695140).

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

21120020101020 is a wasteful number, since it uses less digits than its factorization.

21120020101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77395 (or 77393 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21120020101020 its reverse (2010102002112), we get a palindrome (23130122103132).

The spelling of 21120020101020 in words is "twenty-one trillion, one hundred twenty billion, twenty million, one hundred one thousand, twenty".