211221011221121 has 4 divisors (see below), whose sum is σ = 230422921332144. Its totient is φ = 192019101110100.

The previous prime is 211221011221109. The next prime is 211221011221141. The reversal of 211221011221121 is 121122110122112.

It is a happy number.

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 not a de Polignac number, because 211221011221121 - 2⁴⁶ = 140852267043457 is a prime.

It is a super-2 number, since 2×211221011221121² (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 = 211221011221093 and 211221011221102.

It is not an unprimeable number, because it can be changed into a prime (211221011221141) 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, 9600955055495 + ... + 9600955055516.

It is an arithmetic number, because the mean of its divisors is an integer number (57605730333036).

Almost surely, 2^{211221011221121} is an apocalyptic number.

It is an amenable number.

211221011221121 is a deficient number, since it is larger than the sum of its proper divisors (19201910111023).

211221011221121 is a wasteful number, since it uses less digits than its factorization.

211221011221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19201910111022.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 211221011221121 its reverse (121122110122112), we get a palindrome (332343121343233).

It can be divided in two parts, 2112210 and 11221121, that added together give a palindrome (13333331).

The spelling of 211221011221121 in words is "two hundred eleven trillion, two hundred twenty-one billion, eleven million, two hundred twenty-one thousand, one hundred twenty-one".