201212020021 has 4 divisors (see below), whose sum is σ = 201358570572. Its totient is φ = 201065469472.

The previous prime is 201212020007. The next prime is 201212020027. The reversal of 201212020021 is 120020212102.

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 100640583121 + 100571436900 = 317239^2 + 317130^2 .

It is a cyclic number.

It is not a de Polignac number, because 201212020021 - 2⁵ = 201212019989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201212019983 and 201212020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201212020027) 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, 73273216 + ... + 73275961.

It is an arithmetic number, because the mean of its divisors is an integer number (50339642643).

Almost surely, 2^201212020021 is an apocalyptic number.

It is an amenable number.

201212020021 is a deficient number, since it is larger than the sum of its proper divisors (146550551).

201212020021 is a wasteful number, since it uses less digits than its factorization.

201212020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146550550.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 201212020021 its reverse (120020212102), we get a palindrome (321232232123).

The spelling of 201212020021 in words is "two hundred one billion, two hundred twelve million, twenty thousand, twenty-one".