21201101100220 has 24 divisors (see below), whose sum is σ = 44522784609408. Its totient is φ = 8480350478400.

The previous prime is 21201101100217. The next prime is 21201101100239. The reversal of 21201101100220 is 2200110110212.

It is a self number, because there is not a number n which added to its sum of digits gives 21201101100220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3673651 + ... + 7476490.

It is an arithmetic number, because the mean of its divisors is an integer number (1855116025392).

Almost surely, 2^{21201101100220} is an apocalyptic number.

21201101100220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201101100220 is an abundant number, since it is smaller than the sum of its proper divisors (23321683509188).

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

21201101100220 is a wasteful number, since it uses less digits than its factorization.

21201101100220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11245221 (or 11245219 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21201101100220 its reverse (2200110110212), we get a palindrome (23401211210432).

The spelling of 21201101100220 in words is "twenty-one trillion, two hundred one billion, one hundred one million, one hundred thousand, two hundred twenty".