21000220221006 has 96 divisors (see below), whose sum is σ = 52779011725440. Its totient is φ = 5979160660032.

The previous prime is 21000220220929. The next prime is 21000220221007. The reversal of 21000220221006 is 60012202200012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 21000220221006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000220221007) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 54732036 + ... + 55114391.

It is an arithmetic number, because the mean of its divisors is an integer number (549781372140).

Almost surely, 2^{21000220221006} is an apocalyptic number.

21000220221006 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21000220221006 is an abundant number, since it is smaller than the sum of its proper divisors (31778791504434).

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

21000220221006 is a wasteful number, since it uses less digits than its factorization.

21000220221006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109846510 (or 109846507 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21000220221006 its reverse (60012202200012), we get a palindrome (81012422421018).

The spelling of 21000220221006 in words is "twenty-one trillion, two hundred twenty million, two hundred twenty-one thousand, six".