20211000221221 has 8 divisors (see below), whose sum is σ = 20215544917464. Its totient is φ = 20206455805440.

The previous prime is 20211000221213. The next prime is 20211000221267. The reversal of 20211000221221 is 12212200011202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1726632792196 + 18484367429025 = 1314014^2 + 4299345^2 .

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 20211000221221 - 2³ = 20211000221213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211000221195 and 20211000221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211000221021) 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, 214231741 + ... + 214326061.

It is an arithmetic number, because the mean of its divisors is an integer number (2526943114683).

Almost surely, 2^{20211000221221} is an apocalyptic number.

It is an amenable number.

20211000221221 is a deficient number, since it is larger than the sum of its proper divisors (4544696243).

20211000221221 is an equidigital number, since it uses as much as digits as its factorization.

20211000221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140231.

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

Adding to 20211000221221 its reverse (12212200011202), we get a palindrome (32423200232423).

The spelling of 20211000221221 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one thousand, two hundred twenty-one".