221121201121 has 4 divisors (see below), whose sum is σ = 221122206612. Its totient is φ = 221120195632.

The previous prime is 221121201113. The next prime is 221121201151. The reversal of 221121201121 is 121102121122.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 46638721600 + 174482479521 = 215960^2 + 417711^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121201121 - 2³ = 221121201113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221121201095 and 221121201104.

It is not an unprimeable number, because it can be changed into a prime (221121201151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15406 + ... + 665191.

It is an arithmetic number, because the mean of its divisors is an integer number (55280551653).

Almost surely, 2^221121201121 is an apocalyptic number.

It is an amenable number.

221121201121 is a deficient number, since it is larger than the sum of its proper divisors (1005491).

221121201121 is an equidigital number, since it uses as much as digits as its factorization.

221121201121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005490.

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

Adding to 221121201121 its reverse (121102121122), we get a palindrome (342223322243).

The spelling of 221121201121 in words is "two hundred twenty-one billion, one hundred twenty-one million, two hundred one thousand, one hundred twenty-one".