221111221021 has 4 divisors (see below), whose sum is σ = 234117763452. Its totient is φ = 208104678592.

The previous prime is 221111221007. The next prime is 221111221031. The reversal of 221111221021 is 120122111122.

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 185859280996 + 35251940025 = 431114^2 + 187755^2 .

It is a cyclic number.

It is not a de Polignac number, because 221111221021 - 2⁹ = 221111220509 is a prime.

It is a super-2 number, since 2×221111221021² (a number of 23 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 = 221111220986 and 221111221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111221031) 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, 6503271190 + ... + 6503271223.

It is an arithmetic number, because the mean of its divisors is an integer number (58529440863).

Almost surely, 2^221111221021 is an apocalyptic number.

It is an amenable number.

221111221021 is a deficient number, since it is larger than the sum of its proper divisors (13006542431).

221111221021 is a wasteful number, since it uses less digits than its factorization.

221111221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13006542430.

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

Adding to 221111221021 its reverse (120122111122), we get a palindrome (341233332143).

The spelling of 221111221021 in words is "two hundred twenty-one billion, one hundred eleven million, two hundred twenty-one thousand, twenty-one".