21202212200221 has 8 divisors (see below), whose sum is σ = 22833191064824. Its totient is φ = 19571238973440.

The previous prime is 21202212200161. The next prime is 21202212200291. The reversal of 21202212200221 is 12200221220212.

It can be written as a sum of positive squares in 4 ways, for example, as 338420264121 + 20863791936100 = 581739^2 + 4567690^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21202212200221 - 2¹⁷ = 21202212069149 is a prime.

It is a super-3 number, since 3×21202212200221³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202212200291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9567685 + ... + 11573461.

It is an arithmetic number, because the mean of its divisors is an integer number (2854148883103).

Almost surely, 2^{21202212200221} is an apocalyptic number.

It is an amenable number.

21202212200221 is a deficient number, since it is larger than the sum of its proper divisors (1630978864603).

21202212200221 is a wasteful number, since it uses less digits than its factorization.

21202212200221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2818911.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21202212200221 its reverse (12200221220212), we get a palindrome (33402433420433).

The spelling of 21202212200221 in words is "twenty-one trillion, two hundred two billion, two hundred twelve million, two hundred thousand, two hundred twenty-one".