210220211020021 has 4 divisors (see below), whose sum is σ = 212301599248044. Its totient is φ = 208138822792000.

The previous prime is 210220211020007. The next prime is 210220211020031. The reversal of 210220211020021 is 120020112022012.

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 159258973446225 + 50961237573796 = 12619785^2 + 7138714^2 .

It is a cyclic number.

It is not a de Polignac number, because 210220211020021 - 2⁷ = 210220211019893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210220211019977 and 210220211020004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210220211020031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1040694113860 + ... + 1040694114061.

It is an arithmetic number, because the mean of its divisors is an integer number (53075399812011).

Almost surely, 2^{210220211020021} is an apocalyptic number.

It is an amenable number.

210220211020021 is a deficient number, since it is larger than the sum of its proper divisors (2081388228023).

210220211020021 is a wasteful number, since it uses less digits than its factorization.

210220211020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2081388228022.

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

Adding to 210220211020021 its reverse (120020112022012), we get a palindrome (330240323042033).

The spelling of 210220211020021 in words is "two hundred ten trillion, two hundred twenty billion, two hundred eleven million, twenty thousand, twenty-one".