21000220010020 has 24 divisors (see below), whose sum is σ = 44721595291968. Its totient is φ = 8281776904800.

The previous prime is 21000220009969. The next prime is 21000220010027. The reversal of 21000220010020 is 2001002200012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21000220009979 and 21000220010006.

It is not an unprimeable number, because it can be changed into a prime (21000220010027) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 7394442246 + ... + 7394445085.

It is an arithmetic number, because the mean of its divisors is an integer number (1863399803832).

Almost surely, 2^{21000220010020} is an apocalyptic number.

21000220010020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000220010020 is an abundant number, since it is smaller than the sum of its proper divisors (23721375281948).

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

21000220010020 is a wasteful number, since it uses less digits than its factorization.

21000220010020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14788887411 (or 14788887409 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21000220010020 its reverse (2001002200012), we get a palindrome (23001222210032).

The spelling of 21000220010020 in words is "twenty-one trillion, two hundred twenty million, ten thousand, twenty".