221111102021 has 4 divisors (see below), whose sum is σ = 234117637452. Its totient is φ = 208104566592.

The previous prime is 221111101949. The next prime is 221111102041. The reversal of 221111102021 is 120201111122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120201111122 = 2 ⋅60100555561.

It can be written as a sum of positive squares in 2 ways, for example, as 192908937796 + 28202164225 = 439214^2 + 167935^2 .

It is a cyclic number.

It is not a de Polignac number, because 221111102021 - 2¹⁰ = 221111100997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221111101987 and 221111102005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111102041) 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, 6503267690 + ... + 6503267723.

It is an arithmetic number, because the mean of its divisors is an integer number (58529409363).

Almost surely, 2^221111102021 is an apocalyptic number.

It is an amenable number.

221111102021 is a deficient number, since it is larger than the sum of its proper divisors (13006535431).

221111102021 is a wasteful number, since it uses less digits than its factorization.

221111102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13006535430.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 221111102021 its reverse (120201111122), we get a palindrome (341312213143).

The spelling of 221111102021 in words is "two hundred twenty-one billion, one hundred eleven million, one hundred two thousand, twenty-one".