21200220112221 has 6 divisors (see below), whose sum is σ = 30622540162110. Its totient is φ = 14133480074808.

The previous prime is 21200220112189. The next prime is 21200220112301. The reversal of 21200220112221 is 12221102200212.

It is a happy number.

21200220112221 is a `hidden beast` number, since 21 + 200 + 220 + 1 + 1 + 2 + 221 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13639644989721 + 7560575122500 = 3693189^2 + 2749650^2 .

It is not a de Polignac number, because 21200220112221 - 2⁵ = 21200220112189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200220112194 and 21200220112203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200220113221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1177790006226 + ... + 1177790006243.

It is an arithmetic number, because the mean of its divisors is an integer number (5103756693685).

Almost surely, 2^{21200220112221} is an apocalyptic number.

It is an amenable number.

21200220112221 is a deficient number, since it is larger than the sum of its proper divisors (9422320049889).

21200220112221 is a wasteful number, since it uses less digits than its factorization.

21200220112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2355580012475 (or 2355580012472 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21200220112221 its reverse (12221102200212), we get a palindrome (33421322312433).

The spelling of 21200220112221 in words is "twenty-one trillion, two hundred billion, two hundred twenty million, one hundred twelve thousand, two hundred twenty-one".