212101121200021 has 4 divisors (see below), whose sum is σ = 212101224752844. Its totient is φ = 212101017647200.

The previous prime is 212101121200019. The next prime is 212101121200097. The reversal of 212101121200021 is 120002121101212.

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 168369153809796 + 43731967390225 = 12975714^2 + 6613015^2 .

It is a cyclic number.

It is not a de Polignac number, because 212101121200021 - 2¹ = 212101121200019 is a prime.

It is a super-2 number, since 2×212101121200021² (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 = 212101121199968 and 212101121200004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212101121203021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48640750 + ... + 52821631.

It is an arithmetic number, because the mean of its divisors is an integer number (53025306188211).

Almost surely, 2^{212101121200021} is an apocalyptic number.

It is an amenable number.

212101121200021 is a deficient number, since it is larger than the sum of its proper divisors (103552823).

212101121200021 is a wasteful number, since it uses less digits than its factorization.

212101121200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103552822.

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

Adding to 212101121200021 its reverse (120002121101212), we get a palindrome (332103242301233).

The spelling of 212101121200021 in words is "two hundred twelve trillion, one hundred one billion, one hundred twenty-one million, two hundred thousand, twenty-one".