21210220111021 has 8 divisors (see below), whose sum is σ = 21602747129760. Its totient is φ = 20818794151152.

The previous prime is 21210220111019. The next prime is 21210220111147. The reversal of 21210220111021 is 12011102201212.

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 21210220111021 - 2¹ = 21210220111019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210220110986 and 21210220111004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210220111321) 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, 275225835 + ... + 275302888.

It is an arithmetic number, because the mean of its divisors is an integer number (2700343391220).

Almost surely, 2^{21210220111021} is an apocalyptic number.

It is an amenable number.

21210220111021 is a deficient number, since it is larger than the sum of its proper divisors (392527018739).

21210220111021 is an equidigital number, since it uses as much as digits as its factorization.

21210220111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550529435.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21210220111021 its reverse (12011102201212), we get a palindrome (33221322312233).

The spelling of 21210220111021 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, one hundred eleven thousand, twenty-one".