212100002221021 has 4 divisors (see below), whose sum is σ = 212100039250972. Its totient is φ = 212099965191072.

The previous prime is 212100002221001. The next prime is 212100002221031. The reversal of 212100002221021 is 120122200001212.

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 59639492920921 + 152460509300100 = 7722661^2 + 12347490^2 .

It is a cyclic number.

It is not a de Polignac number, because 212100002221021 - 2³⁵ = 212065642482653 is a prime.

It is a super-2 number, since 2×212100002221021² (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 = 212100002220986 and 212100002221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212100002221001) 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, 7891410 + ... + 22056163.

It is an arithmetic number, because the mean of its divisors is an integer number (53025009812743).

Almost surely, 2^{212100002221021} is an apocalyptic number.

It is an amenable number.

212100002221021 is a deficient number, since it is larger than the sum of its proper divisors (37029951).

212100002221021 is an equidigital number, since it uses as much as digits as its factorization.

212100002221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37029950.

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

Adding to 212100002221021 its reverse (120122200001212), we get a palindrome (332222202222233).

The spelling of 212100002221021 in words is "two hundred twelve trillion, one hundred billion, two million, two hundred twenty-one thousand, twenty-one".