21211200100 has 18 divisors (see below), whose sum is σ = 46028304434. Its totient is φ = 8484480000.

The previous prime is 21211200061. The next prime is 21211200121. The reversal of 21211200100 is 100211212.

It can be written as a sum of positive squares in 3 ways, for example, as 4959539776 + 16251660324 = 70424^2 + 127482^2 .

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

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, 106055901 + ... + 106056100.

Almost surely, 2^21211200100 is an apocalyptic number.

21211200100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211200100 is an abundant number, since it is smaller than the sum of its proper divisors (24817104334).

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

21211200100 is a wasteful number, since it uses less digits than its factorization.

21211200100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212112015 (or 212112008 counting only the distinct ones).

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

Adding to 21211200100 its reverse (100211212), we get a palindrome (21311411312).

The spelling of 21211200100 in words is "twenty-one billion, two hundred eleven million, two hundred thousand, one hundred".