201211212121 has 8 divisors (see below), whose sum is σ = 206618110664. Its totient is φ = 195872325120.

The previous prime is 201211212077. The next prime is 201211212157. The reversal of 201211212121 is 121212112102.

It can be written as a sum of positive squares in 4 ways, for example, as 1550025 + 201209662096 = 1245^2 + 448564^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 201211212121 - 2¹¹ = 201211210073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201211212095 and 201211212104.

It is not an unprimeable number, because it can be changed into a prime (201211212421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16996890 + ... + 17008723.

It is an arithmetic number, because the mean of its divisors is an integer number (25827263833).

Almost surely, 2^201211212121 is an apocalyptic number.

It is an amenable number.

201211212121 is a deficient number, since it is larger than the sum of its proper divisors (5406898543).

201211212121 is an equidigital number, since it uses as much as digits as its factorization.

201211212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34005771.

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

Adding to 201211212121 its reverse (121212112102), we get a palindrome (322423324223).

The spelling of 201211212121 in words is "two hundred one billion, two hundred eleven million, two hundred twelve thousand, one hundred twenty-one".