212102110021 has 4 divisors (see below), whose sum is σ = 212103033292. Its totient is φ = 212101186752.

The previous prime is 212102110001. The next prime is 212102110097. The reversal of 212102110021 is 120011201212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 166749722500 + 45352387521 = 408350^2 + 212961^2 .

It is a cyclic number.

It is not a de Polignac number, because 212102110021 - 2¹³ = 212102101829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212102109983 and 212102110010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212102110001) 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 3 ways as a sum of consecutive naturals, for example, 183271 + ... + 676603.

It is an arithmetic number, because the mean of its divisors is an integer number (53025758323).

Almost surely, 2^212102110021 is an apocalyptic number.

It is an amenable number.

212102110021 is a deficient number, since it is larger than the sum of its proper divisors (923271).

212102110021 is an equidigital number, since it uses as much as digits as its factorization.

212102110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923270.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 212102110021 its reverse (120011201212), we get a palindrome (332113311233).

The spelling of 212102110021 in words is "two hundred twelve billion, one hundred two million, one hundred ten thousand, twenty-one".