21212020221101 has 4 divisors (see below), whose sum is σ = 21221352392412. Its totient is φ = 21202688049792.

The previous prime is 21212020221097. The next prime is 21212020221109. The reversal of 21212020221101 is 10112202021212.

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 18269512261225 + 2942507959876 = 4274285^2 + 1715374^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212020221101 - 2² = 21212020221097 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21212020221101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212020221109) 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, 4666082246 + ... + 4666086791.

It is an arithmetic number, because the mean of its divisors is an integer number (5305338098103).

Almost surely, 2^{21212020221101} is an apocalyptic number.

It is an amenable number.

21212020221101 is a deficient number, since it is larger than the sum of its proper divisors (9332171311).

21212020221101 is an equidigital number, since it uses as much as digits as its factorization.

21212020221101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9332171310.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21212020221101 its reverse (10112202021212), we get a palindrome (31324222242313).

The spelling of 21212020221101 in words is "twenty-one trillion, two hundred twelve billion, twenty million, two hundred twenty-one thousand, one hundred one".