21000020211100 has 144 divisors (see below), whose sum is σ = 52724863892736. Its totient is φ = 7110919296000.

The previous prime is 21000020211097. The next prime is 21000020211133. The reversal of 21000020211100 is 111202000012.

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 47 ways as a sum of consecutive naturals, for example, 181272195 + ... + 181388005.

It is an arithmetic number, because the mean of its divisors is an integer number (366144888144).

Almost surely, 2^{21000020211100} is an apocalyptic number.

21000020211100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000020211100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26362431946368).

21000020211100 is an abundant number, since it is smaller than the sum of its proper divisors (31724843681636).

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

21000020211100 is a wasteful number, since it uses less digits than its factorization.

21000020211100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119036 (or 119029 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21000020211100 its reverse (111202000012), we get a palindrome (21111222211112).

The spelling of 21000020211100 in words is "twenty-one trillion, twenty million, two hundred eleven thousand, one hundred".