20212221021 has 8 divisors (see below), whose sum is σ = 27290762880. Its totient is φ = 13304246592.

The previous prime is 20212221019. The next prime is 20212221053. The reversal of 20212221021 is 12012221202.

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

It is not a de Polignac number, because 20212221021 - 2¹ = 20212221019 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20212221011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42641580 + ... + 42642053.

It is an arithmetic number, because the mean of its divisors is an integer number (3411345360).

Almost surely, 2^20212221021 is an apocalyptic number.

It is an amenable number.

20212221021 is a deficient number, since it is larger than the sum of its proper divisors (7078541859).

20212221021 is an equidigital number, since it uses as much as digits as its factorization.

20212221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85283715.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20212221021 its reverse (12012221202), we get a palindrome (32224442223).

The spelling of 20212221021 in words is "twenty billion, two hundred twelve million, two hundred twenty-one thousand, twenty-one".