20210100221 has 4 divisors (see below), whose sum is σ = 20338827132. Its totient is φ = 20081373312.

The previous prime is 20210100199. The next prime is 20210100247. The reversal of 20210100221 is 12200101202.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6259183225 + 13950916996 = 79115^2 + 118114^2 .

It is a cyclic number.

It is not a de Polignac number, because 20210100221 - 2¹⁰ = 20210099197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20210106221) 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, 64363220 + ... + 64363533.

It is an arithmetic number, because the mean of its divisors is an integer number (5084706783).

Almost surely, 2^20210100221 is an apocalyptic number.

It is an amenable number.

20210100221 is a deficient number, since it is larger than the sum of its proper divisors (128726911).

20210100221 is a wasteful number, since it uses less digits than its factorization.

20210100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128726910.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20210100221 its reverse (12200101202), we get a palindrome (32410201423).

The spelling of 20210100221 in words is "twenty billion, two hundred ten million, one hundred thousand, two hundred twenty-one".