210021212020021 has 8 divisors (see below), whose sum is σ = 210695623349400. Its totient is φ = 209346875432448.

The previous prime is 210021212019937. The next prime is 210021212020057. The reversal of 210021212020021 is 120020212120012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6193080188100 + 203828131831921 = 2488590^2 + 14276839^2 .

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 210021212020021 - 2¹¹ = 210021212017973 is a prime.

It is a super-2 number, since 2×210021212020021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210021212019977 and 210021212020004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210021212050021) 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, 13053796 + ... + 24299053.

It is an arithmetic number, because the mean of its divisors is an integer number (26336952918675).

Almost surely, 2^{210021212020021} is an apocalyptic number.

It is an amenable number.

210021212020021 is a deficient number, since it is larger than the sum of its proper divisors (674411329379).

210021212020021 is a wasteful number, since it uses less digits than its factorization.

210021212020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37370903.

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

Adding to 210021212020021 its reverse (120020212120012), we get a palindrome (330041424140033).

Subtracting from 210021212020021 its reverse (120020212120012), we obtain a palindrome (90000999900009).

The spelling of 210021212020021 in words is "two hundred ten trillion, twenty-one billion, two hundred twelve million, twenty thousand, twenty-one".