221200222021 has 4 divisors (see below), whose sum is σ = 222060923532. Its totient is φ = 220339520512.

The previous prime is 221200222007. The next prime is 221200222043. The reversal of 221200222021 is 120222002122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120222002122 = 2 ⋅60111001061.

It can be written as a sum of positive squares in 2 ways, for example, as 121303137796 + 99897084225 = 348286^2 + 316065^2 .

It is a cyclic number.

It is not a de Polignac number, because 221200222021 - 2¹⁷ = 221200090949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221200221986 and 221200222004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221200222121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 430350370 + ... + 430350883.

It is an arithmetic number, because the mean of its divisors is an integer number (55515230883).

Almost surely, 2^221200222021 is an apocalyptic number.

It is an amenable number.

221200222021 is a deficient number, since it is larger than the sum of its proper divisors (860701511).

221200222021 is an equidigital number, since it uses as much as digits as its factorization.

221200222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860701510.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 221200222021 its reverse (120222002122), we get a palindrome (341422224143).

The spelling of 221200222021 in words is "two hundred twenty-one billion, two hundred million, two hundred twenty-two thousand, twenty-one".