21000220002100 has 18 divisors (see below), whose sum is σ = 45570477404774. Its totient is φ = 8400088000800.

The previous prime is 21000220002079. The next prime is 21000220002119. The reversal of 21000220002100 is 120002200012.

It can be written as a sum of positive squares in 3 ways, for example, as 4756918033296 + 16243301968804 = 2181036^2 + 4030298^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105001099911 + ... + 105001100110.

Almost surely, 2^{21000220002100} is an apocalyptic number.

21000220002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000220002100 is an abundant number, since it is smaller than the sum of its proper divisors (24570257402674).

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

21000220002100 is a wasteful number, since it uses less digits than its factorization.

21000220002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210002200035 (or 210002200028 counting only the distinct ones).

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

Adding to 21000220002100 its reverse (120002200012), we get a palindrome (21120222202112).

The spelling of 21000220002100 in words is "twenty-one trillion, two hundred twenty million, two thousand, one hundred".