21202220012221 has 4 divisors (see below), whose sum is σ = 21271282618432. Its totient is φ = 21133157406012.

The previous prime is 21202220012213. The next prime is 21202220012251. The reversal of 21202220012221 is 12221002220212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21202220012221 - 2³ = 21202220012213 is a prime.

It is a super-2 number, since 2×21202220012221² (a number of 27 digits) contains 22 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 (21202220012251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34531302645 + ... + 34531303258.

It is an arithmetic number, because the mean of its divisors is an integer number (5317820654608).

Almost surely, 2^{21202220012221} is an apocalyptic number.

It is an amenable number.

21202220012221 is a deficient number, since it is larger than the sum of its proper divisors (69062606211).

21202220012221 is an equidigital number, since it uses as much as digits as its factorization.

21202220012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69062606210.

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

Adding to 21202220012221 its reverse (12221002220212), we get a palindrome (33423222232433).

The spelling of 21202220012221 in words is "twenty-one trillion, two hundred two billion, two hundred twenty million, twelve thousand, two hundred twenty-one".