221211012121 has 4 divisors (see below), whose sum is σ = 241321104144. Its totient is φ = 201100920100.

The previous prime is 221211012119. The next prime is 221211012157. The reversal of 221211012121 is 121210112122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221211012121 - 2¹ = 221211012119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221211012095 and 221211012104.

It is not an unprimeable number, because it can be changed into a prime (221211012161) 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, 10055045995 + ... + 10055046016.

It is an arithmetic number, because the mean of its divisors is an integer number (60330276036).

Almost surely, 2^221211012121 is an apocalyptic number.

It is an amenable number.

221211012121 is a deficient number, since it is larger than the sum of its proper divisors (20110092023).

221211012121 is a wasteful number, since it uses less digits than its factorization.

221211012121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20110092022.

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

Adding to 221211012121 its reverse (121210112122), we get a palindrome (342421124243).

The spelling of 221211012121 in words is "two hundred twenty-one billion, two hundred eleven million, twelve thousand, one hundred twenty-one".