221222111210021 has 4 divisors (see below), whose sum is σ = 223707752909100. Its totient is φ = 218736469510944.

The previous prime is 221222111210011. The next prime is 221222111210033. The reversal of 221222111210021 is 120012111222122.

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 18813472502500 + 202408638707521 = 4337450^2 + 14227039^2 .

It is a cyclic number.

It is not a de Polignac number, because 221222111210021 - 2¹⁴ = 221222111193637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221222111209975 and 221222111210002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221222111210011) 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, 1242820849406 + ... + 1242820849583.

It is an arithmetic number, because the mean of its divisors is an integer number (55926938227275).

Almost surely, 2^{221222111210021} is an apocalyptic number.

It is an amenable number.

221222111210021 is a deficient number, since it is larger than the sum of its proper divisors (2485641699079).

221222111210021 is an equidigital number, since it uses as much as digits as its factorization.

221222111210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2485641699078.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 221222111210021 its reverse (120012111222122), we get a palindrome (341234222432143).

The spelling of 221222111210021 in words is "two hundred twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, two hundred ten thousand, twenty-one".