212001020021 has 6 divisors (see below), whose sum is σ = 246613431510. Its totient is φ = 181715159976.

The previous prime is 212001020017. The next prime is 212001020053. The reversal of 212001020021 is 120020100212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 152694159121 + 59306860900 = 390761^2 + 243530^2 .

It is not a de Polignac number, because 212001020021 - 2² = 212001020017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212001019984 and 212001020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212001020521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2163275666 + ... + 2163275763.

It is an arithmetic number, because the mean of its divisors is an integer number (41102238585).

Almost surely, 2^212001020021 is an apocalyptic number.

It is an amenable number.

212001020021 is a deficient number, since it is larger than the sum of its proper divisors (34612411489).

212001020021 is an equidigital number, since it uses as much as digits as its factorization.

212001020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4326551443 (or 4326551436 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 212001020021 its reverse (120020100212), we get a palindrome (332021120233).

The spelling of 212001020021 in words is "two hundred twelve billion, one million, twenty thousand, twenty-one".