21211222200100 has 72 divisors (see below), whose sum is σ = 47025316459688. Its totient is φ = 8302158028800.

The previous prime is 21211222200059. The next prime is 21211222200101. The reversal of 21211222200100 is 100222211212.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 17574138391104 + 3637083808996 = 4192152^2 + 1907114^2 .

It is not an unprimeable number, because it can be changed into a prime (21211222200101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7831119 + ... + 10185718.

Almost surely, 2^{21211222200100} is an apocalyptic number.

21211222200100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211222200100 is an abundant number, since it is smaller than the sum of its proper divisors (25814094259588).

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

21211222200100 is a wasteful number, since it uses less digits than its factorization.

21211222200100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18017105 (or 18017098 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21211222200100 its reverse (100222211212), we get a palindrome (21311444411312).

The spelling of 21211222200100 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, two hundred thousand, one hundred".